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# Using the Pythagorean Theorem: perimeter of a trapezoid

This is a free video lesson where I explain how to calculate the missing sides of a trapezoid using the Pythagorean Theorem when some lengths of sides are known. Lastly I calculate the perimeter. This lesson suits best grades 7-8 or pre-algebra.

Using the Pythagorean Theorem 1: Area of an Isosceles Triangle - a video lesson

Using the Pythagorean Theorem 2: Diagonal of a Square - a video lesson

Using the Pythagorean Theorem 3: volume of a triangular prism - a video lesson

Math Mammoth Grade 7 curriculum (pre-algebra)

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