https://www.khanacademy.org/math/cc-sixth-grade-math/cc-6th-geometry-topic/geometric-solids/v/recognizing-common-3d-shapes 2023-09-15T04:55:18.07520004Z Recognizing common 3D shapes Learn about 3D shapes! A square pyramid has a square base. A rectangular prism is a box shape with all rectangular sides. A triangular prism has triangle faces on opposite sides. A sphere is like a globe. A cylinder looks like a can with circular faces on top and bottom. Shapes are fun! video https://cdn.kastatic.org/ka_thumbnails_cache/269d8dc9-c41f-45fa-9752-bac89194cc97_1280_720_base.png Recognizing common 3D shapes Learn about 3D shapes! A square pyramid has a square base. A rectangular prism is a box shape with all rectangular sides. A triangular prism has triangle faces on opposite sides. A sphere is like a globe. A cylinder looks like a can with circular faces on top and bottom. Shapes are fun! https://cdn.kastatic.org/ka-youtube-converted/tqxQSSzuXX0.mp4/tqxQSSzuXX0.mp4 209 Surface area and volume https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes/x06d55bfa213a79fd:surface-area-of-cuboid-and-cube/v/surface-area-of-a-box-cuboid-indian-accent 2025-06-06T15:33:38.563209632Z Surface area of a box (cuboid) Surface area is total area on the surface of a three-dimensional shape. To find the surface area of a cuboid which has 6 rectangular faces, add the areas of all 6 faces. Or, you can label the length (l), width (w), and height (h) of the cuboid and use the formula: surface area (SA)=2lw+2lh+2hw. Kalakrit (Dubbing) video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Surface area of a box (cuboid) Surface area is total area on the surface of a three-dimensional shape. To find the surface area of a cuboid which has 6 rectangular faces, add the areas of all 6 faces. Or, you can label the length (l), width (w), and height (h) of the cuboid and use the formula: surface area (SA)=2lw+2lh+2hw. https://cdn.kastatic.org/ka-youtube-converted/a_6u4T5nODA.mp4/a_6u4T5nODA.mp4 146 Surface area and volume https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes/x06d55bfa213a79fd:surface-area-of-cuboid-and-cube/v/lateral-surface-area-of-a-cuboid 2025-10-27T12:01:04.888258735Z Lateral surface area of a cuboid Learn how to find the lateral surface area of a cuboid step by step. Starting with the basics, we explore its meaning, showing the unboxing to see which faces count, and then finish with clear calculations. With simple visuals, this video makes the concept quick to grasp and easy to remember. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now! https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes Timestamps: 00:00 - Cuboid Introduction 01:05 - Lateral surface area meaning 02:15 - Unboxing 03:07 - Area calculation 05:37 - LSA calculation Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Khan Academy Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Lateral surface area of a cuboid Learn how to find the lateral surface area of a cuboid step by step. Starting with the basics, we explore its meaning, showing the unboxing to see which faces count, and then finish with clear calculations. With simple visuals, this video makes the concept quick to grasp and easy to remember. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now! https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes Timestamps: 00:00 - Cuboid Introduction 01:05 - Lateral surface area meaning 02:15 - Unboxing 03:07 - Area calculation 05:37 - LSA calculation Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/_BoZ2w8tTo4.mp4/_BoZ2w8tTo4.mp4 402 Surface area and volume https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes/x06d55bfa213a79fd:surface-area-of-cuboid-and-cube/v/surface-area-of-cube 2025-10-27T12:01:04.888258735Z Surface Area of Cube Learn how to find the different surface area of a cube step by step. Starting with the basics, we explore its meaning, showing the unboxing to see which faces count, and then finish with clear calculations. With simple visuals, this video makes the concept quick to grasp and easy to remember. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now! https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes Timestamps: 00:00 - Cube Introduction 00:30 - Total surface area meaning 01:35 - Unboxing 02:45 - Area Calculation 03:30 - TSA calculation 04:05 - Lateral surface area meaning 05:00 - LSA calculation Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Khan Academy Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Surface Area of Cube Learn how to find the different surface area of a cube step by step. Starting with the basics, we explore its meaning, showing the unboxing to see which faces count, and then finish with clear calculations. With simple visuals, this video makes the concept quick to grasp and easy to remember. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now! https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes Timestamps: 00:00 - Cube Introduction 00:30 - Total surface area meaning 01:35 - Unboxing 02:45 - Area Calculation 03:30 - TSA calculation 04:05 - Lateral surface area meaning 05:00 - LSA calculation Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/-YDRlDSDPh4.mp4/-YDRlDSDPh4.mp4 327 Surface area and volume https://www.khanacademy.org/math/geometry/hs-geo-solids/hs-geo-solids-intro/v/solid-geometry-volume 2021-06-30T20:49:30Z Volume of triangular prism & cube Using the formulas for the volume of triangular prism and cube to solve some solid geometry problems. Sal Khan video https://cdn.kastatic.org/googleusercontent/qYxEE09hkJ133DSfdZOZLHTXHSWqvVhLs4UGM4widVZTV46cTQ1be06jB78OdD3esWDEBLZav_lbtyXL-ELc9AUPxg Volume of triangular prism & cube Using the formulas for the volume of triangular prism and cube to solve some solid geometry problems. https://cdn.kastatic.org/ka-youtube-converted/ZqzAOZ9pP9Q.mp4/ZqzAOZ9pP9Q.mp4 236 Surface area and volume https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes/x06d55bfa213a79fd:volume-of-cuboid-cube-right-prism-and-pyramid/v/volume-prism-with-base-as-equilateral-triangle 2025-10-27T12:01:04.888258735Z Volume-Prism with base as equilateral triangle Join us as we derive the general formula for the volume of a right prism and put it into practice with three examples—a cube, a cuboid, and a right prism whose base is an equilateral triangle. We begin by finding the area of the equilateral triangle, then show how multiplying that base area by the prism’s height gives the prism’s volume. Step-by-step worked example and clear visuals make the method easy to follow and apply. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now!Unit link 00:00 Introduction to Right Prism 01:30 Volume of Right Prism 02:50 Volume of Cube 03:35 Volume of Cuboid 04:00 Volume of Equilateral Triangular Prism 06:00 Practice Question Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Khan Academy Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Volume-Prism with base as equilateral triangle Join us as we derive the general formula for the volume of a right prism and put it into practice with three examples—a cube, a cuboid, and a right prism whose base is an equilateral triangle. We begin by finding the area of the equilateral triangle, then show how multiplying that base area by the prism’s height gives the prism’s volume. Step-by-step worked example and clear visuals make the method easy to follow and apply. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now!Unit link 00:00 Introduction to Right Prism 01:30 Volume of Right Prism 02:50 Volume of Cube 03:35 Volume of Cuboid 04:00 Volume of Equilateral Triangular Prism 06:00 Practice Question Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/Fw61jfjMD8Y.mp4/Fw61jfjMD8Y.mp4 413 Surface area and volume https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes/x06d55bfa213a79fd:cylinder/v/surface-area-of-cylinders-formula-indian-accent 2025-06-09T09:58:43.937294419Z Surface area of cylinders formula Use previous knowledge of surface area to make connections to the formulas for lateral and total surface area of cylinders. Courses on Khan Academy are always 100% free. Start practising—and saving your progress—now! (add course link here) Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Kalakrit (Dubbing) video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Surface area of cylinders formula Use previous knowledge of surface area to make connections to the formulas for lateral and total surface area of cylinders. Courses on Khan Academy are always 100% free. Start practising—and saving your progress—now! (add course link here) Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by https://cdn.kastatic.org/ka-youtube-converted/fPWgtycCHvQ.mp4/fPWgtycCHvQ.mp4 240 Surface area and volume https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes/x06d55bfa213a79fd:cylinder/v/cylinder-volume-surface-area-indian-accent 2025-06-04T10:11:55.11792485Z Cylinder volume & surface area A cylinder's volume is π r² h, and its surface area is 2π r h + 2π r². Learn how to use these formulas to solve an example problem. Kalakrit (Dubbing) video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Cylinder volume & surface area A cylinder's volume is π r² h, and its surface area is 2π r h + 2π r². Learn how to use these formulas to solve an example problem. https://cdn.kastatic.org/ka-youtube-converted/Lb6MRln60DQ.mp4/Lb6MRln60DQ.mp4 487 Surface area and volume https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes/x06d55bfa213a79fd:right-circular-cone/v/volume-of-a-cone-indian-accent 2025-06-04T10:04:13.13703146Z Volume of a cone The formula for the volume of a cone is V=1/3hπr². Learn how to use this formula to solve an example problem. Kalakrit (Dubbing) video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Volume of a cone The formula for the volume of a cone is V=1/3hπr². Learn how to use this formula to solve an example problem. https://cdn.kastatic.org/ka-youtube-converted/DpPTwfmOc90.mp4/DpPTwfmOc90.mp4 344 Surface area and volume https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes/x06d55bfa213a79fd:right-circular-cone/v/computing-volume-of-a-cone 2024-01-17T10:08:31.452096345Z Computing Volume of a cone Finding volume of a cone with an example. Devashish Phadnis video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Computing Volume of a cone Finding volume of a cone with an example. https://cdn.kastatic.org/ka-youtube-converted/vrCBP9kXKmE.mp4/vrCBP9kXKmE.mp4 158 Surface area and volume https://www.khanacademy.org/math/revision-term-1-od-math-class-10/x03e14a980a7a91ad:week-3/x03e14a980a7a91ad:mensuration/v/surface-area-of-sphere-computation-and-sense-of-formula 2024-01-17T11:25:19.383730229Z Surface area of sphere: computation and sense of formula Why Is the formula for surface area of sphere equal to 4pir^2? And applying its formula to find the surface area. Devashish Phadnis video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Surface area of sphere: computation and sense of formula Why Is the formula for surface area of sphere equal to 4pir^2? And applying its formula to find the surface area. https://cdn.kastatic.org/ka-youtube-converted/IZ4DpWYO3kY.mp4/IZ4DpWYO3kY.mp4 270 Surface area and volume https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes/x06d55bfa213a79fd:sphere/v/volume-of-a-sphere-indian-accent 2025-06-04T10:04:13.13703146Z Volume of a sphere The formula for the volume of a sphere is V = 4/3 π r³, where V = volume and r = radius. The radius of a sphere is half its diameter. So, to calculate the volume of a sphere given the diameter of the sphere, you can first calculate the radius, then the volume. Kalakrit (Dubbing) video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Volume of a sphere The formula for the volume of a sphere is V = 4/3 π r³, where V = volume and r = radius. The radius of a sphere is half its diameter. So, to calculate the volume of a sphere given the diameter of the sphere, you can first calculate the radius, then the volume. https://cdn.kastatic.org/ka-youtube-converted/tFcmjvpIyhM.mp4/tFcmjvpIyhM.mp4 155 Surface area and volume https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes/x06d55bfa213a79fd:hemisphere/v/surface-area-of-a-hemisphere 2025-10-27T12:01:04.888258735Z Surface area of a hemisphere In this video, we explore the surface area of a hemisphere—a three-dimensional shape that's half of a sphere. You'll learn the difference between curved surface area and total surface area, understand the formulas behind each, and see how they’re derived step by step. With clear visuals and real-world examples, we make the concept easy to grasp and apply. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now!Unit link 00:00 Surface area of sphere 00:47 CSA of hemisphere 01:27 TSA of hemisphere 02:42 Practice Question Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Khan Academy Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Surface area of a hemisphere In this video, we explore the surface area of a hemisphere—a three-dimensional shape that's half of a sphere. You'll learn the difference between curved surface area and total surface area, understand the formulas behind each, and see how they’re derived step by step. With clear visuals and real-world examples, we make the concept easy to grasp and apply. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now!Unit link 00:00 Surface area of sphere 00:47 CSA of hemisphere 01:27 TSA of hemisphere 02:42 Practice Question Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/Uwnuy5HwYZs.mp4/Uwnuy5HwYZs.mp4 210 Surface area and volume https://www.khanacademy.org/math/class-9-tg/x06d55bfa213a79fd:surface-areas-and-volumes/x06d55bfa213a79fd:hemisphere/v/volume-of-a-hemisphere 2025-10-27T12:01:04.888258735Z Volume of a hemisphere In this video, we explore the volume of a hemisphere—a three-dimensional shape that's half of a sphere. You'll learn the formula for calculating its volume, understand how it's derived, and see how it compares to the volume of a full sphere. We also walk through a practice question step by step to help reinforce the concept and build confidence. With clear visuals and intuitive explanations, this lesson makes 3D geometry feel simple and approachable—perfect for students preparing for exams or anyone curious about how shapes hold space. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now!Unit link 00:00 Volume of sphere- Introduction 00:45 Volume of hemisphere 01:15 Practice Question Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Khan Academy Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Volume of a hemisphere In this video, we explore the volume of a hemisphere—a three-dimensional shape that's half of a sphere. You'll learn the formula for calculating its volume, understand how it's derived, and see how it compares to the volume of a full sphere. We also walk through a practice question step by step to help reinforce the concept and build confidence. With clear visuals and intuitive explanations, this lesson makes 3D geometry feel simple and approachable—perfect for students preparing for exams or anyone curious about how shapes hold space. Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now!Unit link 00:00 Volume of sphere- Introduction 00:45 Volume of hemisphere 01:15 Practice Question Khan Academy India is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We have videos and exercises that have been translated into multiple Indian languages, and 15 million people around the globe learn on Khan Academy every month. Support Us: https://india.khanacademy.org/donate Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/4ocKazhuc1Y.mp4/4ocKazhuc1Y.mp4 146 Surface area and volume https://www.khanacademy.org/math/revision-tg-math-class-9/x6c9499d6e7016acd:week-2/x6c9499d6e7016acd:surface-area-and-volume/e/revision-surface-area-and-volume-tg-class-9 2026-02-18T21:20:35.275198076Z Revision surface area and volume TG class 9 . Khan Academy exercise