If the curved surface area of a cone is 4070 cm2 and its diameter is

1.	If the curved surface area of a cone is 4070 cm2 and its diameter is 70 cm, then its slant height isA) 27 cm B) 37 cm C) 47 cm D) 57 cm
Answer» Correct option is: B) 37 cm Curved surface area of cone is 4070 \(cm^2\) i.e. \(\pi rl\) = 4070 ....(1) Also given that diameter of cone is 70 cm. \(\therefore\) 2r = 70 cm. = r = \(\frac {70}2 = 35 \, cm\) \(\therefore\) l = \(\frac {4070}{\pi r} =\frac {4070}{22 \times 35} \) (From (1)) = \(\frac {814}{22}\) = 37 cm. Hence, the slant height of the cone is 37 cm. Correct option is: B) 37 cm

If the curved surface area of a cone is 4070 cm2 and its diameter is 70 cm, then its slant height isA) 27 cm B) 37 cm C) 47 cm D) 57 cm

Answer»

Correct option is: B) 37 cm

Curved surface area of cone is 4070 \(cm^2\)

i.e. \(\pi rl\) = 4070 ....(1)

Also given that diameter of cone is 70 cm.

\(\therefore\) 2r = 70 cm.

= r = \(\frac {70}2 = 35 \, cm\)

\(\therefore\) l = \(\frac {4070}{\pi r} =\frac {4070}{22 \times 35} \) (From (1))

= \(\frac {814}{22}\) = 37 cm.

Hence, the slant height of the cone is 37 cm.

Correct option is: B) 37 cm