Question

The curved surface area of a cone is 4070 cm² and its diameter is 70cm. What is its slant height?

Answer 1

Given:
Curved surface area of the cone = 4070 cm²
Diameter = 70 cm
∴ Radius (r) = $\frac{70}{2}$ cm = 35 cm
We know:
Curved surface area of a cone = $\mathrm{\pi }$rl
$\Rightarrow$4070 = $\frac{22}{7}\times 35\times l$

$\Rightarrow$l = $\frac{4070\times 7}{22\times 35}$ = 37 cm