Question

A toy is in the shape of a hemisphere surmounted by a cone. If radius of base of the cone is 3 cm and its height is 4 cm, the total surface area of the toy is

• A. 33 $\pi cm^2$
• B. 42 $\pi cm^2$
• C. 66 $\pi cm^2$
• D. 56 $\pi cm^2$

Answer 1

Answer: (A)

33 $\pi cm^2$

Answer 2

Surface area of hemisphere=2$\pi$r2
= 2$\pi$(3)2 = 18$\pi$сm2
Surface area of cone = $\pi$rl
l=$\sqrt{4^2 + 3^2}$ = 5
Area $\pi$×3×5=15$\pi$ cm2
Total surface area = 18$\pi$+ 15$\pi$= 33$\pi$ cm2
So the correct option is (A)