Question

A cone has same volume with a cylinder which is 5 cm high. If they have same area of the

bases and the cylinder has volume 451 cm", find the area of the surface of the cone

Answer 1

Explanation:

Remember, the formulas for the lateral surface area of a pyramid is 12pl and the total surface area is 12pl+B .

Since the base of a cone is a circle, we substitute 2πr for p and πr2 for B where r is the radius of the base of the cylinder.

So, the formula for the lateral surface area of a right cone is L.S.A=πrl , where l is the slant height of the cone.

Find the lateral surface area of a right cone if the radius is 4 cm and the slant height is 5 cm.

L.S.A=π(4)(5)=20π≈62.82 cm2