Question

using paper mache a student made a right circular hollow cone of height 15 cm and radius of base 8 cm. He then has to paint this cone from outside and inside both. Find the total surface area that has to be painted

Answer 1

r= 8cm
h=15cm
so l square = r square + h square
so l square = 64+225
So l= underroot of 289
So long = 17cm
area to be painted from outside = CSA= pie×r×l
3.14×8×17= 427.04
area to be painted from inside =427.04
total area to be painted=427.04+427.04
=854.08