Question

Angle XYZ is rotated 270 degrees counterclockwise about the origin to form angle X’Y’Z’. Which statement shows the measure of angle X’Y’Z’?
m∠X’Y’Z’ = m∠XYZ
m∠X’Y’Z’ = 180 degrees
m∠X’Y’Z’ = 270 degrees
m∠X’Y’Z’ = 2 × m∠XYZ

Answer 1

It is fine that you did not include the measure of angle XYZ in your posting.

This question is testing your knowledge of the four types of transformations.
1) Translations - an item is "slid" to a new location.
2) Reflections - an item is "flipped" (usually over the x-axis or y-axis)
3) Rotations - an item is rotated, usually around the origin (the point (0,0) is the center of most rotations, especially in high school math).
4) Dilations - an item is enlarged or reduced by a certain ratio.

It the first three, the image after the transformation is congruent to the pre-image.  It has the same size and shape.  It is simply flipped, rotated, slid...

But... in the fourth, dilation, the image now has a different size.  It is still, however the same shape.

In geometry terms, after the first three transformations, the image is still "congruent" to the pre-image.  After dilation, the image is "similar" but not "congruent."

So... all that to say that when you rotate an angle around the origin, the measure of the angle doesn't change.

So the first choice is correct.  The measure of the image of the angle is the same as the measure of the angle.
m∠X’Y’Z’ = m∠XYZ

Answer 2

Answer:m∠X’Y’Z’ = m∠XYZ

Step-by-step explanation: