Three semicircles are placed in a rectangle, as shown below. The length of the rectangle is 30 m . Find the area of the shaded region. Use the value for , and do not round your answer. Be sure to include the correct unit in your answer.

Respuesta :

Answer:

The area of the shaded region is: 32.25m^2

Step-by-step explanation:

Given

See attachment for rectangle and semicircles

Required

The shaded region

We have:

[tex]l =30[/tex] --- length of the rectangle

This means that the diameters of the three circles add up to 30m.

So, the diameter of 1 is:

[tex]d = l/3[/tex]

[tex]d = 30/3[/tex]

[tex]d = 10[/tex]

The area of one circle is:

[tex]A_1 = \pi * \frac{d^2}{8}[/tex]

[tex]A_1 = 3.14 * \frac{10^2}{8}[/tex]

[tex]A_1 = 3.14 * \frac{100}{8}[/tex]

[tex]A_1 = 39.25m^2[/tex]

The area of the three circles is:

[tex]A_2 = 3 * A_1[/tex]

[tex]A_2 = 3 *39.25m^2[/tex]

[tex]A_2 = 117.75m^2[/tex]

The area of the rectangle is:

[tex]A_3 = 30 * r[/tex]

Where r is the radius of the circle

And

[tex]r =d/2[/tex]

[tex]r =10/2[/tex]

[tex]r =5[/tex]

So, we have:

[tex]A_3 = 30 * r[/tex]

[tex]A_3 = 30 * 5[/tex]

[tex]A_3 = 150[/tex]

So, the shaded region is:

[tex]A_4 = A_3 - A_2[/tex]

[tex]A_4 = 150 - 117.75[/tex]

[tex]A_4 = 32.25m^2[/tex]

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