Question

Find the total surface area of a cone if it's slant height is 21 cm and diameter of its base is 24 cm

Answer 1

Answer:

Value of total surface area of cone will be $\approx 1244.57\:cm^2$

Step-by-step explanation:

In context to question asked,

We have to determine the total surface area of cone,

As per question,

We have,

Slant height of cone = l = 21 cm

Diameter of cone = 24 cm

So, radius of cone will be $\frac{24}{2} = 12\:cm$

As we have, the formula for finding the total surface area of cone which is $\Pi r(r + l)$

Where 'r' is the radius of the right circular cone and 'l' is the slant height of the right circular cone.

So, for determining the total surface area of cone,

We will put the value given in question in above formula,

Thus we will get,

$\Pi r(r + l)\\\frac{22}{7} \times 12 \times (12+21)\\\frac{22}{7} \times 12 \times 33\\\frac{8712}{7} = 1244\frac{4}{7} \:cm^2 \approx 1244.57\:cm^2$

Answer 2

Step-by-step explanation:

T.S.A of cone = πr(r+l)

22/7×12×33= 1244.5 m square

hope this answers is helpful