Question

if radius of base of a cone is 14 cm and its slant height is 9 m.find the (1) curved surface area (2) total surface area​

Answer 1

Answer:

C. S. A. = 396 cm²

T. S. A. = 650.5 cm²

Step-by-step explanation:

Given -

Radius of cone (r) = 14 cm

Slant height of cone (l) = 9 cm

To find -

Curved Surface Area (C. S. A.) and Total Surface Area (T. S. A.) of cone

Solution -

C. S. A. of cone = πrl

$= \frac{22}{7} \times 9 \times 14 {cm}^{2} \\ = \frac{22 \times 9 \times 14}{7} {cm}^{2} \\ = 22 \times 9 \times 2 {cm}^{2} \\ = 396 {cm}^{2}$

T. S. A of cone = πr (l + r)

$= \frac{22}{7} \times 9 \times (14 + 9) {cm}^{2} \\ = \frac{22}{7} \times 9 \times 23 {cm}^{2} \\ = \frac{4554}{7} {cm}^{2} \\ = 650.5 {cm}^{2}$

Approximately.

Hence C. S. A of cone = 396 cm² and T. S. A. of cone = 650.5 cm² (approx).

hope it helps.