A toy is in the form of a cone of radius 3.5cm mounted on a hemisphere of same radius. The total height of the toy is 15.5cm. Find the total surface area of the toy
Answers
Answer:
Radius of cone = 3.5 cm
height of cone =15.5–3.5=12cm
Slant height of cone can be calculated as
l=√h^2+√r^2
=√12^2+√3.5^2
=√144+√12.25
=√156.25 =12.5 cm
Curved surface area of cone can be calculated as
= pi*r*l
=22/7 × 3.5 x 12.5
= 137.5 sq cm
Curved surface area of hemispherical portion can be calculated as
=pi*r*r
=2 x 22/7 x 3.5 x 3.5
=77 sq cm
Hence, total surface area 137.5+77=214.5 sq cm
Step-by-step explanation:
Answer:
We have,
Radius of cone = Radius of hemisphere = 3.5 cm.
Height of the toy = 15.5 cm
To calculate the CSA of cone we have to find first the Slant Height of the cone :]
Slant Height = h² + r²
Slant Height = (15.5)² + (3.5)²
Slant Height = 12.25 + 144
Slant Height = 156.25 cm²
Slant Height = 12.5 cm
Now, we will calculate the TSA of the toy :
➳ TSA of toy = CSA of hemisphere + CSA of cone
➳ TSA of toy = 2πr² + πrl
➳ TSA of toy = 2π(3.5)² + π(3.5)(12.5)
➳ TSA of toy = 24.5π + 43.75π
➳ TSA of toy = 68.25π
➳ TSA of toy = 68.25 * 22/7
➳ TSA of toy = 214.5 cm²