A toy in the form of cone of radius 3.5 cm mounted on a hemisphere of same radius. The total height of the toy is 15.5 cm, find the total surface area of toy.
Total surface area of toy = Curved surface area of cone + surface area of hemisphere
Curved surface area of cone = πrl
Where r=3.5cm, Height =15.5−3.5=12cm
And hence, l=12.5cm (by using formula l2=h2+b2)
Therefore C.S.A. of cone =π×3.5×12.5
=137.5cm2
Surface area of hemisphere =2πr2
=2×π×(3.5)2
=77cm2
Hence T.S.A of toy =77+137.5=214.5cm2