Help me find this geometry question?

The perimeter of the segment:

[12 + 24 pi (1/6)] inches

= 24.566370614359172 inches

Arc length = 2πr (m∠O)/360 = 2π(12)(60)/360 = 4π

Perimeter of segment = Arc length + r + r = 4π + 12 + 12 = 36.6 in

The perimeter=12(pi/3)+12=24.56637 in. approximately.

Since OA is a radius of the circle, OB is a radius as well and its length is also 12 in.

The triangle is therefore isosceles and the measures of the angles at A and B are equal.

The sum of the angles of any triangle is 180°. The angle at O is 60° leaving 120° for the other two. They are equal and thus all three angles are 60°.

The triangle is thus equilateral and all sides are equal.

The length of segment AB is 12 inches.

The angle at O is 60° which is 1/6 of "all the way around" (360°). The circumference of the circle is the diameter times pi, 24 in × π, and one-sixth of that is 4 × π in. (This is approximately 12.566 inches, but the question says "exact.")

The exact perimeter is 12 + 4π inches.

YOU'RE the one in summer school. Do it yourself.