Question

Find the area of the shaded regions. Give your answer as a completely simplified exact value in terms of π (no approximations).

Answer 1

Answer:

$40\pi \ m^{2}$

Step-by-step explanation:

we know that

The area of a circle is equal to

$A=\pi r^{2}$

In this problem we have

$r=10\ m$

Substitute and find the area

$A=\pi (10)^{2}=100 \pi\ m^{2}$

Remember that

$360\°$ subtends the area of complete circle

so

by proportion

Find the area of the shaded regions

The central angle of the shaded regions is equal to $2*72\°=144\°$

$\frac{100\pi }{360} \frac{m^{2}}{degrees} =\frac{x }{144} \frac{m^{2}}{degrees} \\ \\x=144*100\pi /360\\ \\ x=40\pi \ m^{2}$