B. is the answer to your question!! Hope this helps!! :D
Answer:
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
