Question

alicia draws an equilateral triangle and then rotates it about its center. through which angle measures can she rotate the equilateral triangle to map it onto itself? select each correct answer. 60° 90° 120° 180° 240° 300°

Answer 1

" select each correct answer " the correct answers are 120 and 240, just took the test....

Answer 2

120°, 240°

Explanation:

An equilateral triangle has 3 equal sides and 3 equal angles.

To rotate the equilateral triangle onto itself, we have to rotate each of those sides to an adjacent side. This happens when the angle of turn is
`(1)/(3)`th of a full-circle turn.

A circle has
`360^(\circ)` and
`(1)/(3)* 360^(\circ)=120^(\circ)`.

Therefore, a 120° rotation clockwise or counterclockwise puts each of the edges over the position where an adjacent edge was located.

Any angle which is a multiple of 120° will also do the same. So the answers should be 120°, 240°.