The curved surface area of a cone is 308cm2 and its slant height is 1

1.	The curved surface area of a cone is 308cm2 and its slant height is 14cm. Find the radius of the base and total surface area of the cone.
Answer» Consider r as the radius of the cone It is given that Slant height of the cone = 14cm Curved surface area of the cone = 308cm² It can be written as πrl = 308 By substituting the values (22/7) × r × 14 = 308 On further calculation 22 × r × 2 = 308 So we get r = 308/ (22 × 2) r = 7cm We know that Total surface area of a cone = πr (l + r) By substituting the values Total surface area of a cone = (22/7) × 7 × (14 + 7) On further calculation Total surface area of a cone = 22 ×21 = 462 cm² Therefore, the base radius of the cone is 7cm and the total surface area is 462 cm².

The curved surface area of a cone is 308cm2 and its slant height is 14cm. Find the radius of the base and total surface area of the cone.

Answer»

Consider r as the radius of the cone

It is given that

Slant height of the cone = 14cm

Curved surface area of the cone = 308cm²

It can be written as

πrl = 308

By substituting the values

(22/7) × r × 14 = 308

On further calculation

22 × r × 2 = 308

So we get

r = 308/ (22 × 2)

r = 7cm

We know that

Total surface area of a cone = πr (l + r)

By substituting the values

Total surface area of a cone = (22/7) × 7 × (14 + 7)

On further calculation

Total surface area of a cone = 22 ×21 = 462 cm²

Therefore, the base radius of the cone is 7cm and the total surface area is 462 cm².