11.9k views
5 votes
What are all of the answers for these questions? Use 3 for pi. Please do not use a file to answer, I cannot read it.Question 8.

What are all of the answers for these questions? Use 3 for pi. Please do not use a-example-1

1 Answer

5 votes

To calculate the area of the doughnut, we need to calculate the area of the larger circle and substract the area of the smaller circle.

The area of a circle can be calculated using its radius:


A=\pi r^2

The diameter of the larger circle is 6cm which meand that its radius is half as large, so the radius is 3 cm and the area of the larger circle is:


A_L=\pi3^2=9\pi

Area of 9π cm².

The smaller one have a diameter of 2 cm, so its radius is half as large, radius of 1 cm.

So, the area of the smaller circle is:


A_S=\pi1^2=\pi

Area of π cm².

The total shaded area is, then, the area of the larger minus the area of the smaller.

So, the shaded area is:


\begin{gathered} A=A_L-A_S \\ A=(9\pi-\pi)cm^2 \\ A=8\pi cm^2 \\ A\approx(9\cdot3)cm^2 \\ A\approx27cm^2 \end{gathered}

User LxL
by
7.2k points