Question

The figure below is dilated by a scale factor of 4 to form angle, X, prime, Y, prime, Z, prime∠X
′
Y
′
Z
′
. What is the measure of angle, X, prime, Y, prime, Z, prime∠X
′
Y
′
Z
′
?

Answer 1

A dilation is a similarity transformation, so it preserves angle measures. Therefore m∠X′Y′Z′ = m∠XYZ — the image angle has exactly the same measure as the original angle.