Question

The diameter of a circle is 18 cm. What is its are in terms of π.a. 324 π cm^2b. 180 π cm^2c. 81 π cm^2d. 18 π cm^2

Answer 1

Step-by-step explanation

The formula to calculate the area of a circle is:

`\begin{gathered} A=\pi r^2 \\ \text{ Where} \\ A\text{ is the area} \\ r\text{ is the radius} \end{gathered}`

So, we have:

`r=\frac{\text{ diameter}}{2}=(18cm)/(2)=9cm`
`\begin{gathered} A=\pi r^(2) \\ A=\pi(9cm)^2 \\ A=81\pi cm^2 \end{gathered}`Answer

81π cm²