https://www.khanacademy.org/math/class-7-ncf/x063f95a40c290960:expressions-using-letter-numbers/x063f95a40c290960:simplification-of-algebraic-expression-part-1/v/perimeter-of-a-rectangle-using-variables-algebra-class-6-india-math-khan-academy 2020-11-03T12:02:05Z Perimeter of a rectangle using variables Let's learn how to write the perimeter for any rectangle in the language of mathematics using variables. Aanand Srinivas video https://cdn.kastatic.org/googleusercontent/SRQdQqrIxPmCDDenrBHmd13YhPRzfFo19Y94jicYJpASbRMeHVZLgC904KO71jhAW_2bnXEI-rPi38eKC6Kq5g0o Perimeter of a rectangle using variables Let's learn how to write the perimeter for any rectangle in the language of mathematics using variables. https://cdn.kastatic.org/ka-youtube-converted/EnKre0h2An4.mp4/EnKre0h2An4.mp4 330 Perimeter and area https://www.khanacademy.org/math/class-7-ncf/x063f95a40c290960:expressions-using-letter-numbers/x063f95a40c290960:the-notion-of-letter-numbers/v/perimeter-of-a-square-using-variables-algebra-class-6-india-math-khan-academy 2020-10-07T19:09:49Z Perimeter of a square using variables Let's learn how to write the perimeter for any square in the language of mathematics using variables. Aanand Srinivas video https://cdn.kastatic.org/googleusercontent/apoLmdVvrLsKeff_g4For8ZKF80v-RYsNGy_Sdo9JruyibZldcGis60Q0kF17We4PPVRVs10pVHgfs6dL9ibSTmw Perimeter of a square using variables Let's learn how to write the perimeter for any square in the language of mathematics using variables. https://cdn.kastatic.org/ka-youtube-converted/ezPWpQit2FU.mp4/ezPWpQit2FU.mp4 275 Perimeter and area https://www.khanacademy.org/math/revision-mr-class-7-term-2/x34b615b2e8bb343d:week-2-revision-mr-class-7-term-2-math/x34b615b2e8bb343d:perimeter-and-area/v/comparing-areas-word-problem-indian-accent 2025-06-06T15:33:38.563209632Z Comparing areas word problem Sal compares the area of two posters using their side-lengths. Skyloom (Dubbing) video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Comparing areas word problem Sal compares the area of two posters using their side-lengths. https://cdn.kastatic.org/ka-youtube-converted/0c0omE8x5ts.mp4/0c0omE8x5ts.mp4 136 Perimeter and area https://www.khanacademy.org/math/class-6-ncf/x04ca845a9a148c80:perimeter-and-area/x04ca845a9a148c80:area-of-triangle/v/area-of-a-triangle-indian-accent 2025-06-06T15:33:38.563209632Z Area of a triangle The area of a rectangle and a parallelogram is found by multiplying the base by the height. For a triangle, the area is half of a parallelogram's, so it's calculated by multiplying the base by the height and then dividing by 2. Skyloom (Dubbing) video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Area of a triangle The area of a rectangle and a parallelogram is found by multiplying the base by the height. For a triangle, the area is half of a parallelogram's, so it's calculated by multiplying the base by the height and then dividing by 2. https://cdn.kastatic.org/ka-youtube-converted/qK-UUd3IlqQ.mp4/qK-UUd3IlqQ.mp4 326 Perimeter and area 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 Perimeter and area https://www.khanacademy.org/math/revision-mr-class-7-term-2/x34b615b2e8bb343d:week-2-revision-mr-class-7-term-2-math/x34b615b2e8bb343d:perimeter-and-area/e/revision-perimeter-and-area 2026-01-28T03:50:33.306290623Z Revision perimeter and area . Khan Academy exercise