Question

a circular lid has a diameter of 24 cm. a = π · 12² the area of the lid is about square cm.

Explanation:

Step1: Recall area formula for circle

The area formula of a circle is $A = \pi r^{2}$, where $r$ is the radius. Given diameter $d = 24$ cm, the radius $r=\frac{d}{2}=\frac{24}{2}=12$ cm.

Step2: Substitute radius into formula

Substitute $r = 12$ into $A=\pi r^{2}$, we get $A=\pi\times(12)^{2}=144\pi$ square - cm.

Answer:

$144\pi$