Mensurationmedium · Past Paper

The total surface area of a right circular cone is 90π cm². If its radius is 5 cm, find its slant height.

A13 cm
B12 cm
C15 cm
D10 cm

✓ Correct Answer: A13 cm

πr(r+l) = 90π => 5(5+l) = 90 => 5+l = 18 => l = 13 cm.

Share this question

More from Mensuration