Question

Observe the given figure and answer the following questions: 

1. How many surfaces does a solid cone have?

2. What are the names of slant height and perpendicular height in the given figure?

3. If slant height of solid cone is 10 cm and perpendicular height is 8 cm, then find diameter of base of solid cone?

Answer 1

a. A solid cone has two surfaces.

b. The name of the slant height is PA or PB and the name of the perpendicular height is PO.

c. l² = r² + h²

∴ 10² = r² + 8²

∴ r² = 100 – 64

∴ r² = 36

∴ r = `sqrt(36)`

∴ r = 6

Radius of base of the cone is 6 cm

∴ Diameter of the base = 2 × radius

= 2 × 6

= 12 cm

Diameter of the base is 12 cm.