Question

A toy is in the shape of radius 3.5cm mounted on a hemisphere of same radius.total height of the toy is 15.5cm.find the total surface area of the toy

Answer 1

Given:

• Radius of cone = 3.5 cm
• Height of toy = 15.5 cm

To Find:

• Total surface area of toy.

Solution:

☯ Toy is hemispherical at bottom and conical at top.

Therefore,

T.S.A of toy = C.S.A of hemisphere + C.S.A of cone

★Slant height of cone, l = √h² + r²

→ l = √3.5² + 12²

→ l = √12.25 + 144

→ l = √156.25

→ l = 12.5 cm

Therefore,

★ 2πr² + πrl

→ 2π (3.5)² + π(3.5)(12.5)

→ 24.5π + 43.75π

→ 68.25π

→ 68.25 × 22/7

→ 214.5 cm²

⠀

Hence,

• Total surface area of toy is 214.5 cm².