Question

!30 POINTS! How can I use this trapezoid to prove the Pythagorean Theorem?

Answer 1

Pythagorean Theorem: c2 = a2 + b2

Find the area by adding the areas of the three triangles. The area of a right triangle is: A = ½bh

Two triangles are identical so you can just multiply the area of the first triangle by two: 2A1 = 2(½bh) = 2(½ab) = ab.

The total area of the trapezoid is : A1 + A2 = ab + ½c2

You multiply both sides by 2 to get rid of the ½: (a2 + 2ab + b2) = 2ab + c2

You subtract out the 2ab: a2 + b2 = c2.

Then what is left is the proof: a2 + b2 = c2