The angles that measure 90° are called right angles, so the correct option is C.
What is a 90° angle?
A 90° angle is the one we get when two perpendicular lines intersect (we actually get four of these).
And are the same ones that we can see on squares or rectangles, where the connecting sides are perpendicular between them.
The name of that type of angle, as one could imagine, is Right Angle (for the nature of the intersection that conforms them). So the correct option is C.
If you want to learn more about right angles, you can read:
https://brainly.com/question/17972372
