Question

small cone with radius 3 centimetre is cut from the upper portion of the radius of the circular base is 12cm

Answer 1

Answer:

Given, r1=12cm,h1=20cm,r2=3cm,h2=?

We know, r2r1=h2h1

∴312=h220

∴h2=123×20=5cm

∴ The cut to be made at 5cm from the vertex.

Volume of the frustum=31πh(r12+r22+r1r2)

=31×722×15(122+32+12×3)=7110×