Question

Pls answer giving 100 points

Answer 1

A = (81 - 20.25π)cm²

P = (18 + 9π)cm

Explanation:

Since the answer asks for the exact value, we will keep π as itself to ensure there is no rounding off errors.

Firstly, finding the area A.

> Putting both semicircles together, you will get a full circle. Hence, finding the area only requires you to subtract the circle off the square.

>Also, the radius of the circle is
`(9)/(2)=4.5`.

Thus,

`A=9^(2) -(\pi *4.5^(2) )\\A= 9^(2)-20.25\pi\\A= (81-20.25\pi)cm^(2)`

Next, finding the perimeter B.

>Again, combining both arcs of the shaded figure together, we form a circumference of the circle.

Thus,

`P = 2(9) + (2*\pi *4.5)\\=(18+9\pi )cm`