What is the measure of arc rc?

30°

60°

90°

120°

The correct answer for this question would be the last option: 120°. So how did we get 120°? Take note that the triangle is inside a circle. A circle is 360°. So, the triangle inside is an equilateral triangle. Therefore, all the arcs inside the circle are also equal. So what we are going to do is divide 360 by 3 and we get 120. Which makes the answer 120°. I hope that this answer helps.

What am i doing here. add?