Question

the radius and vertical height of a cone are 5cm and 12 CM respectively find its curved surface area

Answer 1

r = 5cm
h = 12cm
l = ?
l^2 = h^2 + r^2
l^2 = (12)^2 + (5)^2
l^2 = 144 + 25
l^2 = 169
l = 13
nom we have
l = 13cm , h = 12cm or r = 5cm
CSA of cone = 22/7 × r × l
CSA = 22/7 × 5 × 13
CSA = 1430/7
CSA = 204.28

Answer 2

Answer:

The curved surface area of the cone will be 204.28cm².

Step-by-step explanation:

Given:-

Radius of the cone (r) = 5cm

Vertical height of the cone (h) = 12cm

We know that, curved surface area of cone is πrl where l is the arc length.

Therefore, first we need to find the arc length by using pythagoras theorem:

$l^{2}=r^{2}+h^{2}$

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

$l=\sqrt{ 5^{2}+12^{2}}$

$l=\sqrt{ 25+144}$

$l=\sqrt{ 169}$

$l=13$

Thus, the arc length is 13cm.

Hence, the curved surface area of cone =  πrl

Curved surface area of cone =  22/7 × 5 × 13

Curved surface area of cone =  204.28cm²

∴The curved surface area of the cone will be 204.28cm².

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