Question

A toy is in the form of a cone of radius 3.5 cm mounted on a hemipshere of same radius.The total height of the toy is 15.5 cm.Find the total surface of the toy.

Answer 1

As per the parameters given in the question, we have

Radius of the conical portion of the toy = 3.5 cm = r

Total height of the toy = 15.5 cm = h

Length of the cone = L = 15.5 – 3.5 = 12 cm

Now,

The curved surface area of the cone = πrL = SA

SA = π (3.5) (12)

SA = 131.94 cm²

The curved surface area of the hemisphere = 2πr² = S

S = 2π ( 3.5 )²

S = 76.96 cm²

Therefore, The total surface area of the toy = Curved surface area of the cone + curved surface area of the hemisphere = TSA

TSA = 131.94 + 76.96

TSA = 208.90 cm²

Hence, the total surface area of the children’s toy = TSA = 209 cm²