Explanation -:
1) Find the curved surface area of a cylinder with the height and radius 4 CM and 7 CM respectively.
In this question we are provided with the radius of a cylinder and a height of the cylinder. We are asked to calculate the curved surface area of the cylinder.
We know,
Curved surface area = 2πrh
Where,
- r stand for radius
- h stand for height
- Assuming π as 3.14
Substituting the values we get
Curved surface area = (2 × 3.14 × 4 × 7) cm²
→ Curved surface area = (6.28 × 28) cm²
→ Curved surface area= 175.84 cm²
- Hence the curved surface area of the cylinder is 175.84 cm²
2) Find the circular surface area of the cylinder when the radius is 14 CM.
In this question we are provided with the radius of the cylinder. We are asked to calculate the area of the cylinder.
We know,
Area of a cylinder = πr²
Where,
- r stand for radius
- Assuming π as 3.14
Area = (3.14 × 14²) cm²
→ Area = 3.14 × 14 × 14
→ Area = 615.44cm²
- Hence the area of the cylinder is 615.44 cm²
3) Find the circular surface area of the cylinder when the diameter is 7CM.
In this question we are provided with the diameter of the cylinder. We are asked to calculate the area.
First we will calculate the radius
Radius = Diameter/ 2
Substituting the values we get
Radius = 7/2 cm
Radius = 3.5 cm
Now we will calculate the area of the cylinder
We know,
Area of the cylinder = πr²
Area = 3.14 × 3.5²
→ Area = 3.14 × 3.5 × 3.5
→ Area = 38.465 cm²
- Hence the area of the cylinder is 38.465 cm².