Question

Calculate the area of a circle with a diameter of 12 cm​

Answer 1

we know its diameter is 12, thus its radius must be half that, or 6.

$\bf \textit{area of a circle}\\\\ A=\pi r^2~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ r=6 \end{cases}\implies A=\pi 6^2\implies A=36\pi \implies A\approx 113.097$