Question

from the top of a solid cone of height 22•5cm and base radius 12cm , a cone of height 7•5cm is cut to form frustum what is the total surface of frustum​

Answer 1

Step-by-step explanation:

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×(144+9

Answer 2

Answer:

is the correct answer dear