1. Find the area of the circle. You know the radius = 10 in. Use
[tex]a = \pi {r }^{2} [/tex]
2. Find the area of the (I'm assuming) equilateral triangle. Use the 30-60-90 rule to determine the length of half one of the edges, since you already know the hypotenuse of the 30-60-90 triangle. Multiply that value by 2 to get the length of one side. Then use
[tex]a = \frac{ \sqrt{3} }{4} {l}^{2} [/tex]
to find the area, where l = length of one side.
3. Subtract the area of the equilateral triangle from the area of the circle to find the area of the shaded region.
Hope this helps. Let me know if you're confused!
