Question

a toy is in the form of a cone mounted on a hemisphere the diameter of the base and the height of a cone are 8 cm and 3 cm respectively determine the surface area of the toy use pie equal to 3.14​

Answer 1

Answer:

Given :

 For cone -

1. Height of the cone = 4cm

2. diameter of the cone = 6cm

3.radius of the cone = = 3cm

Slant height of the cone l = √r²+h²

⇒ l = √3²+4²

⇒ l = √9+16

⇒ l = 5

Lateral surface area of the cone = πrl

⇒ 3.14 × 3 × 5

⇒ 3.14 × 15

⇒ 47,10 cm²

For Hemisphere -

1. Diameter of the hemisphere = 6cm

2. Radius of hemisphere = = 3cm

Lateral surface area of hemisphere = 2πr²

⇒ 2 × 3.14 × 3²

⇒ 2 × 3.14 × 9

⇒ 18 × 3.14

⇒ 56.52 cm²

The surface are of toy = lateral surface area of cone + lateral surface area of                                      hemisphere

⇒ 47.10 + 56.52

⇒ 103.62cm³ 

∴ The total surface area of toy = 103.62cm³

Answer 2

Step-by-step explanation: Radius of cone = 8/2  = 4 cm  

  slant height of the cone   L = √R² + H²   ⇒ L =  16 + 9 = 25 then L = 5

lateral surface area of cone = πrl

                                                = 3.14 ×4 ×5

                                                =  62.8 cm²  

 now lateral surface area of hemisphere  = 2πr²

                                                                        = 2 ×3.14 ×4²

                                                                         = 100.48 cm²

surface area of toy = lateral surface area of cone +  lateral surface area of hemisphere

                                = ( 62.8 +100.48 ) cm²

                                = 163.28 cm²