Question

Two identical cones are joined as shown in the figure. If the radius of the base is 4 cm and the slant height of the cone is 6 cm, then the height of the solid is:

Options

• 8 cm

• `4sqrt(5)` cm

• `2sqrt(5)` cm

• 12 cm

Answer 1

`bb(4sqrt5 "cm")`

Explanation:

Radius (r) = 4 cm

Slant height (l) = 6 cm

We know

l² = h² + r²

h² = (6)² – (4)²

h² = 36 – 16

h² = 20

h = `sqrt(20)`

h = `2sqrt(5)` cm

Total height of solid = `2sqrt5 + 2sqrt5 = 4sqrt5` cm