Math, asked by aasys704, 4 months ago

calculate the surface area of cone whose siant height is 21 m and diameter is 24 m

Answers

Answered by danielyohannan01
0

Answer:

Slant height of cone is l=21 m.

Diameter of its base is d=24 m.

hence, radius of its base is r = d/2

=12 m.

Now, the total surface area of cone is given by

S=πrl+πr ²

S=π(rl+r²)

S=π(12×21+12²)

S=π(252+144)

S= 22/7 ×396

S=1244.57 m²

Surface Area = 1244.57 m²

Answered by Saby123
1

Solution :

Diameter of Cone = 24 m

> Radius of cone = 12 m.

The slant height of this cone is 21 m.

Let us assume that the height of the cone is h m.

> h^2 + (12)^2 = (21)^2

> h^2 = (21)^2 - (12)^2

> h^2 = (33)(9)

h = 3 root 33 .

To find : Total surface area of the cone

> pi r l + pi r^2

r = 12 cm and l = 21 cm

> pi * 12 * 21 + pi * 21 * 21

> 252 pi + 441 pi

> 693 pi

> 693 * 22/7

>  2178 m^2 .

This is the required answer

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