Question

perpendicular height of a cone is 120 cm and it's slant height is 13cm find the radius of the base of the cone. ​

Answer 1

Answer:

Given perpendicular height of a cone is 12 cm and its slant height is 13 cm. we have to find the radius of base of cone.

By Pythagoras theorem

AC^2=AB^2+BC^2

⇒ l^2=h^2+r^2

⇒ 13^2=12^2+r^2

⇒ 169=144+r^2

⇒ r^2=169-144=25

The radius is r=5 cm

Answer 2

Answer:

Maybe it's perpendicular height = 12 cm

${(slant \: \: height)}^{2} = {(perpendicular \: \: height \:) }^{2} + {(radius)}^{2} \\ \\ {(13)}^{2} = {(12)}^{2} + {(r)}^{2} \\ \\ 169 = 144 + {r}^{2} \\ \\ {r}^{2} = 169 - 144 \\ \\ {r}^{2} = 25 \\ \\ r = 5 \: cm$