Question

how do I solve this I know the circumference, area and arc length formulas but I don't understand how to find the diameter of the area is 201.1?

Answer 1

the formula for the area of the circle is

$A=\pi r^2$

it is given that the area of the circle is 201.1

$\begin{gathered} 201.1=\frac{22}{7}\times r^2 \\ r^2=\frac{201.1\times7}{22} \\ \end{gathered}$$\begin{gathered} r^2=\frac{1407.7}{22}=63.98 \\ r=\sqrt[]{63.98}\text{ or }\sqrt[]{64} \\ r=7.98\text{ }\approx8 \end{gathered}$

we know that the diameter of the circle is twice of the radius

so, diameter D = 2r = 2 x 8 = 16

so the answer is approx 16