Question:
The surface area of a sphere is $5544 \mathrm{~cm}^{2}$ find its diameter.
Solution:
Surface area of a sphere is $5544 \mathrm{~cm}^{2}$
$4 \pi r^{2}=5544$
$4 \times 3.14 \times(r)^{2}=5544$
$r^{2}=\frac{5544 \times 7}{88}$
$\mathrm{r}=\sqrt{21 \mathrm{~cm} \times 21 \mathrm{~cm}}$
r = 21cm
Diameter = 2(radius)
= 2(21) = 42 cm