Question

Find the total surface area of cone whose diameter of base is $14m$ and slant height is $25m$.

Answer 1

Given:

Slant height =25m

Base Diameter = 14m

We know that slant height is = $\sqrt{h^2+r^2}=25$,

By putting in the given values we got;

$h^2+7^2=625$

$h^2=576$

h=24 m

Total surface are of cone = Base area + curved surface area

$=\pi r^2+\pi rl$

$=\frac{22}{7}\times 7^2+\frac{22}{7}\times 7\times 25$

$=704m^2$