The surface area of a sphere is 5544 cm2,
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