Question

Consider Triangle ABC with A(-2,4), B(-2,-4), C(4,-4) and Triangle A'B'C'

with A'(-5,10), B'(-5,-10), C'(10,-10) Prove ABC ~ A'B'C'

Answer 1

Find the scale factor of the corresponding points. If the scale factor is the same for all points the triangles are similar.

A (-2, 4) x 2.5 = A’ (-5,10)

B(-2,4) x 2.5 = B’(-5,10)

C(4,-4) x 2.5 = C’(10,-10)

All three points have a scale factor of 2.5 so the two triangles are similar.