Question

The radius and the height of a cone are in the ratio 3:4 if it's volume is 301.44cm cube what is its radius? what is its slant height? (Take pie=3.14)

Answer 1

Answer:

let the radius be 3x and height be 4x

given V=301.44cm³

we know that V=1/3πr²h

301.44=1/3×3.14×3x×3x×4x

301.44/3.14=12x³

96=12x³

x³=8

x=2cm

therefore,radius=3x=3×2=6cm   height=4x=4×2=8cm

now,

we know that Curved Surface Area of cone=πrl

where l is slant height

l=√r²+h²

l=√6²+8²

l=√36+64

l=√100

l=10cm

now  of cone =3.14×6×10

=188.4 cm²