Question

Find the curved surface area of a right circular cone whose slant height is 25 cm and radius of the base is 7 cm.

Answer 1

Hint – In this particular type of question we have to find the curved surface area of a right circular cone, we need apply the formula for curved surface area of the cone which is to multiply the base radius of cone and the slant height of cone by $\pi $ to get the desired curved surface area of the cone.

Complete step-by-step answer:

We know that the curved surface area of the cone is $\pi rl$, where r is the radius of the base and l is the slant height of the cone respectively.
Therefore putting the values of r = 7cm and l = 25cm from the question, we get
Curved surface area = $\dfrac{{22}}{7} \times 7 \times 25$
 $ = 22 \times 25 = 550c{m^2}$

Note – Remember to recall the formula of Curved surface area and draw a figure to visualize such questions properly. Always remember to not confuse altitude with the slant height in a cone as altitude is the perpendicular to the base and slant height is the line joining the edge of the base and the top of the cone.