What is the total surface area of a right circular cone of height 14 cm and base radius 7 cm?
344.35 $cm^2$
462 $cm^2$
498.35 $cm^2$
None of these
Explanation:
h = 14 cm, r = 7 cm.
So, l = $ \sqrt{(7)^2 + (14)^2} = \sqrt{245} = 7\sqrt{5} cm$
ஃ Total surface area = $\pi$ rl + $\pi r2$
= $(\dfrac{22}{7} \times 7 \times 7\sqrt{5} + \dfrac{22}{7} \times 7 \times 7 ) cm^2 $
= $[154(\sqrt{5} + 1)] cm^2 $
= (154 x 3.236) $cm^2$
= 498.35 $cm^2.$
h = 14 cm, r = 7 cm.
So, l = $ \sqrt{(7)^2 + (14)^2} = \sqrt{245} = 7\sqrt{5} cm$
ஃ Total surface area = $\pi$ rl + $\pi r2$
= $(\dfrac{22}{7} \times 7 \times 7\sqrt{5} + \dfrac{22}{7} \times 7 \times 7 ) cm^2 $
= $[154(\sqrt{5} + 1)] cm^2 $
= (154 x 3.236) $cm^2$
= 498.35 $cm^2.$