Question

Find the circumference and the area of a circle of diameter 35 cm.

Answer 1

Given:
Diameter, d = 35 cm
Thus, we have:
$$\begin{gathered} r=\frac{d}{2} \\ r=\frac{35}{2}\mathrm{cm} \end{gathered}$$

Now,
Circumference of the circle = $2\pi r$
$$\begin{gathered} =2\times \frac{22}{7}\times \frac{35}{2} \\ =110\mathrm{cm} \end{gathered}$$

Area of the circle = $\pi r^2$
$$\begin{gathered} =\frac{35}{2}\times \frac{35}{2}\times \frac{22}{7} \\ =962.5{\mathrm{cm}}^2 \end{gathered}$$