Question

The diameter of a sphere is $21$ m. Find its surface area and volume.

Answer 1

Diameter $=21$ m
Surface area $=4\pi r^2=\pi d^2$
$=\pi (21{)}^2$
$=65.94m^2$
Volume of sphere $=\frac{4}{3}\pi r^3=\frac{\pi }{6}{d}^3$
$=\frac{\pi }{6}\times {21}^3$
$=4846.59m^3$