Question

Given: ∆BCA is a right triangle.
Prove: a2 + b2 = c2


The two-column proof with missing justifications proves the Pythagorean Theorem using similar triangles.

Statement
Justification
Draw an altitude from point C to

Let = a
= b
= c
= h
= x
= y

y + x = c



a2 = cy; b2 = cx

a2 + b2 = cy + b2

a2 + b2 = cy + cx

a2 + b2 = c(y + x)

a2 + b2 = c(c)

a2 + b2 = c2



Which is NOT a justification for the proof?

Addition Property of Equality

Pythagorean Theorem

Pieces of Right Triangles Similarity Theorem

Cross Product Property

Answer 1

ooh i know this

Answer 2

http://www.khanacademy.org/math/algebra/ck12-algebra-1/v/visual-pythagorean-theorem-proof

Answer 3

video proof