Question

Find the c.s. A of a Cone whose height is 12cm and has radius is 5cm ?​

Answer 1

$\huge\star\underline{\mathtt\red{A}\mathtt\green{N}\mathtt\blue{S}\mathtt\purple{W}\mathtt\orange{E}\mathtt\pink{R}}\star\:$

Height of cone - 12cm

Radius of cone - 5cm

In order to find out the C.S.A ( Curved surface area ) of the the cone we need to find out the slant height of the cone .

Slant height - $\sqrt{r² + h²}$

=> $\sqrt{(5)²+ (12)²}$

=> $\sqrt{25 + 144}$

=> $\sqrt{169}$

=> 13 cm

Now ,

C.S.A = πrl

=> $\dfrac{22}{7}$ × 5 × 13

=> $\dfrac{22×5×13}{7}$

=> $\dfrac{1430}{7}$

=> $\dfrac{\cancel{1430}}{\cancel{7}}$

=> 204.28 cm²