from cylinder with base 5cm&ht.12cm aconical cavity with same base&ht. is carved out,find?

Question

find the whole surface area of the remaining solid

mention all steps and answer

Answer 1

By base do you mean base radius or base diameter? I will assume you mean radius.

Let
r = radius cylinder
h = height cylinder
S = surface area remaining cylinder (including bottom)

S = πr² + 2πrh + πr√(r² + h²) = πr[r + 2h + √(r² + h²)]
S = π*5[5 + 2*12 + √(5² + 12²)]
= 5π[5 + 24 + 13] = 5π(42) = 210π