A cone has a height of 12cm and its base has a radius of 15cm. If the cone is horizontally cut into two segments 3cm from the base, what would the surface area of the bottom segment be?

1 Answer
Jan 2, 2017

Total surface area of bottom segment is 1500.5(1dp) sq.cm

Explanation:

The cone is cut at 3 cm from base, So upper radius of the frustum of cone is r2=1231215=11.25cm ; slant ht l=32+(1511.25)2=9+14.0625=23.0625=4.80cm

Top surface area At=π11.252=397.61 sq.cm
Bottom surface area Ab=π152=706.858 sq.cm
Slant Area As=πl(r1+r2)=π4.80(15+11.25)=396.03 sq.cm

Total surface area of bottom segment =At+Ab+As=397.61+706.86+396.03=1500.5(1dp)sq.cm[Ans]