Question

4. The radius and height of the cone are 5cm and 10cm respectively. find the curved surface area?​

Answer 1

Given :

• Radius (r) of cone = 5 cm
• Height (h) of cone = 10 cm

To find :

• Curved surface area of cone

Solution :

The curved surface area of cone is given by :

$\boxed{ \sf \large{\orange{ csa \: of \: cone = \pi rl}}}$

π = 22/7

r = 5 cm

l = ?

The slant height (l) of a right circular cone is given by :

$\implies\boxed{ \tt l = \sqrt{ {r}^{2} + {h}^{2} } }$

$\tt \: = \sqrt{ {5}^{2} + {10}^{2} } \\ \\ \tt= \sqrt{25 + 100} \\ \\ = \tt \sqrt{125} \\ \\ \boxed{ \tt= 11.18 \: cm}$

CSA = πrl

$= \tt \dfrac{22}{7} \times 5 \times 11.18 \\ \\ = \tt\frac{1229.8}{7} \\ \\ \boxed{ = \tt 175.68 \: {cm}^{2} }$