https://www.khanacademy.org/math/cc-third-grade-math/3rd-perimeter/imp-perimeter/v/introduction-to-perimeter 2023-04-19T11:35:31.910148755Z Perimeter: introduction Perimeter is a math concept that measures the total length around the outside of a shape. To find the perimeter, you add together the lengths of all the sides. This works for any shape, including triangles, rectangles, pentagons, and even irregular polygons. Sal Khan video https://cdn.kastatic.org/googleusercontent/aTvq7f3uGIpqeoqnKTdxUkoGyVejTcBvBXqaj7wzF4xDy1JAs8xn1oz1vrTQbSsF6zh-V3eQkAXzKg0hNkdL7sqR Perimeter: introduction Perimeter is a math concept that measures the total length around the outside of a shape. To find the perimeter, you add together the lengths of all the sides. This works for any shape, including triangles, rectangles, pentagons, and even irregular polygons. https://cdn.kastatic.org/ka-youtube-converted/9uwLgf84p5w.mp4/9uwLgf84p5w.mp4 201 Perimeter of 2D figures https://www.khanacademy.org/math/cc-third-grade-math/3rd-perimeter/perimeter-of-polygons-with-missing-side-lengths/v/finding-perimeter-when-a-side-length-is-missing-math-3rd-grade-khan-academy 2023-05-12T21:01:01.897246564Z Finding perimeter when a side length is missing The video is teaching us how to find the perimeter of a shape. To do this, we need to measure the lengths of all the sides and add them together. Sometimes we have to use clues to figure out the length of a side if it isn't labeled. The perimeter is the total distance around the outside of the shape. Lindsay Spears video https://cdn.kastatic.org/googleusercontent/EdrpJv2GJY-cKYAF2JeQKw4svuNSuBCxPPH7BMpnrC7LTeqwF6eHXRRZIZNDaHkS9VTmOAvfZxhJ_rFSQ_9Va-to Finding perimeter when a side length is missing The video is teaching us how to find the perimeter of a shape. To do this, we need to measure the lengths of all the sides and add them together. Sometimes we have to use clues to figure out the length of a side if it isn't labeled. The perimeter is the total distance around the outside of the shape. https://cdn.kastatic.org/ka-youtube-converted/tmt5fXhU7Rs.mp4/tmt5fXhU7Rs.mp4 211 Perimeter of 2D figures https://www.khanacademy.org/math/cc-third-grade-math/3rd-perimeter/imp-perimeter/e/perimeter-2 2025-02-10T05:04:39.155459793Z Find perimeter when given side lengths Find perimeter of figures when given an image or context.   Lindsay Spears exercise https://www.khanacademy.org/math/cc-third-grade-math/3rd-perimeter/perimeter-of-polygons-with-missing-side-lengths/v/finding-missing-a-side-length-when-given-perimeter-math-3rd-grade-khan-academy 2023-04-19T11:35:31.910148755Z Finding missing side length when given perimeter The video illustrates how to find the lengths of unknown sides on a shape by using the given perimeter and the lengths of known sides. Two examples are given, and in each case, the missing side lengths are determined to be 5 units. Lindsay Spears video https://cdn.kastatic.org/googleusercontent/SR9KKRii0BvLtSZDwoLs7pD--qohmq-m4voTY1cPpTe3Qj303N2tLyVCNTB1OUwyazNz2EAD48PNonW4NknfEAnv Finding missing side length when given perimeter The video illustrates how to find the lengths of unknown sides on a shape by using the given perimeter and the lengths of known sides. Two examples are given, and in each case, the missing side lengths are determined to be 5 units. https://cdn.kastatic.org/ka-youtube-converted/_sQ3dqhLsIw.mp4/_sQ3dqhLsIw.mp4 295 Perimeter of 2D figures https://www.khanacademy.org/math/cc-third-grade-math/3rd-perimeter/perimeter-of-polygons-with-missing-side-lengths/e/find-a-missing-side-length-when-given-perimeter 2025-06-24T14:43:14.98588327Z Find a missing side length when given perimeter Find a missing side length for a figure when given the perimeter. Lindsay exercise https://www.khanacademy.org/math/geometry-home/geometry-area-perimeter/geometry-perimeter/v/perimeter-and-unit-conversion 2020-06-23T07:22:43Z Perimeter and unit conversion Sal converts metric unit to help solve a perimeter problem. Sal Khan video https://cdn.kastatic.org/googleusercontent/QujpILvQYdtYBDW2UfUSQHUzebh8Kz-JFNt0MZaVa6qk4UzAeetNCDvvZkeK2pIP37VGQLnYCY_xdu-tXuFkfhGG Perimeter and unit conversion Sal converts metric unit to help solve a perimeter problem. https://cdn.kastatic.org/ka-youtube-converted/q9XCrpLPfGk.mp4/q9XCrpLPfGk.mp4 373 Perimeter of 2D figures https://www.khanacademy.org/math/geometry-home/geometry-area-perimeter/geometry-perimeter/v/applying-the-metric-system 2023-05-12T21:01:01.897246564Z Applying the metric system to perimeter How do you find width of a rectangle if given a length and a perimeter? First, make sure that your units match. Once the units match, use the formula for the perimeter of a rectangle (2 times the length plus 2 times the width) to solve for the width. Sal Khan video https://cdn.kastatic.org/googleusercontent/HAPmBw9kwsySUsZM2W7pkuAYOeODltW65F4QjyPJN1WO0hav6bjaXWr5KCrc6XcmJAgVw0ZLjreL03LnWFTJw8g Applying the metric system to perimeter How do you find width of a rectangle if given a length and a perimeter? First, make sure that your units match. Once the units match, use the formula for the perimeter of a rectangle (2 times the length plus 2 times the width) to solve for the width. https://cdn.kastatic.org/ka-youtube-converted/CDvPPsB3nEM.mp4/CDvPPsB3nEM.mp4 343 Perimeter of 2D figures https://www.khanacademy.org/math/cc-third-grade-math/3rd-perimeter/imp-perimeter/a/perimeter-review 2021-06-30T20:49:27Z Perimeter review Review the basics of perimeter and try some practice problems. article https://www.khanacademy.org/math/cc-third-grade-math/3rd-perimeter/imp-perimeter-word-problems/v/perimeter-word-problem-tables-math-3rd-grade-khan-academy 2021-06-30T20:49:33Z Perimeter word problem: tables Lindsay solves a perimeter word problem that involves combining two perimeters. Lindsay Spears video https://cdn.kastatic.org/googleusercontent/uEaK6n3-ALTgBEux8Zxq48V8YA4LMssvDeEA7pAAxhMyEZ5BWfxHSFH-wDSn5LXWlqZHsCO_M0G_lRdP5-RcpQM27g Perimeter word problem: tables Lindsay solves a perimeter word problem that involves combining two perimeters. https://cdn.kastatic.org/ka-youtube-converted/Wz8grvnFDHM.mp4/Wz8grvnFDHM.mp4 240 Perimeter of 2D figures