Question

A toy is in the shape of a right circular cylinder with a hemisphere on one end and a cone on the other. The radius and height of the cylindrical part are 5 cm and 13 cm respectively.The radii of the hemispherical and conical parts are the same as that of the cylindrical part. Find the surface area of the toy if the total height of the toy is 30 cm.

Answer 1

Total height= 30cm
Height of cylinder =13cm
Height of cone = 30-18 = 12 (radius of hemisphere=height)
Therefore height of cone= 12 cm
C.S.A. of hemisphere = 2× $\pi$ × $5^2$
=157.14 $c{m}^2$
C.S.A. of cylinder = 2 × $\pi$ × 5 ×13
=408.571 $c{m}^2$
C.S.A of cone = $\pi$ rl = $\frac{22}{7}$ × 5 × 13 =204.28 $c{m}^2$
Adding all C.S.A of cylinder

= 157.14 $c{m}^2$ + 408.571 $c{m}^2$ + 204.28 $c{m}^2$ = 769.99 $c{m}^2$