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Find the area and perimeter of the shaded regions below. Give your answer as a completely simplified exact value in terms of pi (no approximations). The figures below are based on semicircles or quarter circles.

*I found the area but I can't seem to find the perimeter

Find the area and perimeter of the shaded regions below. Give your answer as a completely-example-1

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Answer:


A=(8 \pi +40) cm^2


P=(4 \pi + 4\sqrt {29}) \: cm

Explanation:

For semicircle:

Diameter = 8 cm

Radius (r) = 8/2 = 4 cm

For triangle:

Base (b) = 8 cm

Height (h) = 10 cm

Area of the shaded region


A=\frac {1}{2} \pi r^2 +\frac {1}{2}b.h


A=\frac {1}{2} \pi (4)^2 +\frac {1}{2}(8).(10)


A=(8 \pi +40) cm^2

By Pythagoras Theorem:


AC = BC = \sqrt {4^2 +10^2}


AC = BC = \sqrt {16 +100}


AC = BC = \sqrt {116}


AC = BC =2\sqrt {29}


P= \frac {1}{2} * 2\pi r+ AC + BC


P= \pi (4)+ 2\sqrt {29} + 2\sqrt {29}


P=(4 \pi + 4\sqrt {29}) \: cm

User Karthick Aravindan
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