Answer:
Step-by-step explanation:
The formula for finding the area of a pentagon(regular) given 1 side is
A = [tex]\frac{1}{4}\sqrt{5(5+2\sqrt{5})}s^{2}\)[/tex]
s (the side) = 12
Area = [tex]\frac{1}{4}\sqrt{5(5+2\sqrt{5})}12^{2}\)[/tex]
Area = [tex]\frac{1}{4}\sqrt{5(5+2\sqrt{5})}144\)[/tex]
Area = sqrt(5(5 + 2*2.2361) * 36
Area = sqrt(5( 5 + 4.4721)) * 36
Area = sqrt(5*9.4721) * 36
Area = sqrt(47.3606) * 36
Area = 6.882 * 36
Area = 247.7485
The area of the circle = pi r*2 but we don't have r.
If you know any trig, the formula for the radius of the circle is
R = s/(2*sin(180)/n) n = 5 because you are using a 5 sided figure.
R = 12/(2*sin(180/5)
R = 12/2* sin(36)
R = 6 / sin(36)
R = 10.207
So the area of the circle is pi * R^2
Area = 3.14 * 10.2078^2
Area = 327.1854
The area of the shaded part is the difference between the 2 areas we found
Answer: 327.1854 - 247.7485
Answer: 79.44
