Question

a sequence of transformations is described below.

• a rotation about a point p
• a translation
• a rotation about another point q
• a vertical stretch about the horizontal line pq

which of the following must be preserved under this sequence of transformations?
choose 1 answer
a angle measures only
b segment lengths only
c both angle measures and segment lengths
d neither angle measures nor segment lengths

Explanation:

• Rotations and translations are rigid transformations. Rigid transformations preserve both angle measures and segment lengths.
• A vertical stretch about a horizontal line is a non - rigid transformation. But in the case of a vertical stretch, angle measures are preserved.

Answer:

A. Angle measures only