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How do you find the area of the shaded region and using units

How do you find the area of the shaded region and using units-example-1
User Johnson
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1 Answer

14 votes
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To find the area of the shaded region you divide the figure into:

2 semicircles and one triangle, as fllow:

First semicircle and triangle:

Second semicircle:

The area of the shaded area is the sum of Area 1 and 2 (semicircle and triangle) less the area of semicircle 3.


A_S=A_1+A_2-A_3Area 1:

The area of a semicircle is:


A=(\pi\cdot r^2)/(2)

The semicirlce 1 has a diameter of (4cm+4cm+8cm=16cm) the radius is the half of the diameter (8cm):


A_1=\frac{\pi\cdot(8\operatorname{cm})^2}{2}=(\pi64cm^2)/(2)=32\pi cm^2Area 2:

The area of a triangle is:


A=(1)/(2)b\cdot h

The given triangle has height of 3cm and a base of 8cm:


A_2=(1)/(2)(8\operatorname{cm})(3\operatorname{cm})=(24cm^2)/(2)=12cm^2

Area 3:

The semicirlce has a diameter of 8cm, the radios os the hal od the diameter (4cm):


A_3=\frac{\pi\cdot(4\operatorname{cm})^2}{2}=(\pi16cm^2)/(2)=8\pi cm^2

Then, the area of the shaded region is approximately: 87.40 squared centimeters
\begin{gathered} A_S=32\pi cm^2+12cm^2-8\pi cm^2 \\ \\ A_S=24\pi cm^2+12cm^2 \\ \\ A_S\approx87.40cm^2 \end{gathered}

How do you find the area of the shaded region and using units-example-1
How do you find the area of the shaded region and using units-example-2
User Rob Davies
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2.8k points