Question

the surface area of a sphere of radius 5 centimetre is five times the area of the curved surface of a cone of radius 4 cm find the height and the volume of the cone​

Answer 1

Answer:

A/Q

4πr² = 5πr(l+r)

4*5*5 = 5 *4 (l+4) {pi are cancelled}

100. =. 20 (l+4)

100/20 =l+4

5 = l+4

l = 5-4

slant height = 1

Now,

slant height =√(r²+h²)

1. =√4²+h²)

1. = 16 + h²{sq.root is carried}

h². = 15

h. =3.872cm

volume of a cone=1/3πr²*h

= 1/3*22/7*3.875

= 28.416cm³

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