Question

The dashed triangle is the image of the solid triangle. The center of dilation is (−5, 7) .

What is the scale factor used to create the dilation?

Enter your answer as an integer or decimal in the box.

Answer 1

Just took the test and the answer is -0.25

Hope this helps future people :-)

Answer 2

Before dilation:
the height of the triangle is h₁ = 7 - (-1) = 8
the width of the triangle is w₁ = 7 - (-5) = 12

After dilation:
the height of the is h₂ = 9-7 = 2
the width of the triangle is w₂ = -5 - (-8) = 3

The scale factor is h₂/h₁ = 2/8 = 1/4 = 0.25
Also, the scale factor is w₂/w₁ = 3/12 = 1/4 = 0.25

Answer: The scale factor is 0.25