Question

the hight and radius of a cone are 3 and 4 m respectivly find a curved surface area

Answer 1

h=3
r=4
l²=h²+r²
=3²+4²
=9+16
=25
l=5
csa of cone =pi*r*l
=22/7*5*4
=22/7*20
=440/7m²

Answer 2

$\huge\underline\mathrm{GivEn:-}$

Height of cone = 3m

Radius of cone = 4m

$\huge\underline\mathrm{To\:Find:-}$

Find the Curved Surface Area of the Cone

$\huge\underline\mathrm{SoLution:-}$

We have given that the height and radius of cone are 3m and 4m respectively.

Firstly, we need to find the Slant height (l) of the cone

To find, the Slant height of the cone, we use the formula:- $l = \sqrt{ {h}^{2} + {r}^{2} }$

$\implies$$l = \sqrt{ {(3)}^{2} + {(4)}^{2} }$

$\implies$$l = \sqrt{9 + 16}$

$\implies$$l = \sqrt{25}$

$\implies$$\large\bf{l = 5 \: m}$

Now, we have to find C.S.A. of cone

We know that the formula to find the C.S.A. of cone is:- $\large\rm{πrl}$

Putting the given values in the formula

$\implies$ C.S.A. = $\large{\sf {\frac{22}{7}}}$$\times$ 4 $\times$ 5

$\implies$ C.S.A. = $\large{\sf {\frac{440}{7}}}$

$\implies$ C.S.A. = 62.85 m²

Thus, the Curved Surface area of cone is 62.85 m²

$\huge\underline\mathrm{ThAnKs...}$