find the volume curved surface area and total surface area of a cylinder having diameter 21 cm and height 18 cm
Answers
Step-by-step explanation:
Diameter = 21cm
Let us find out radius,
radius= diameter /2
hence, radius = 21cm/2
height = 18cm
Curved surface area = 2πrh
= 2 × 22/7 × 21/2 × 18 ( π = 22/7 )
= 1188cm²
volume = πr²h
= 22/7 × 21/2 × 21/2 × 18
= 6237cm³
hope it helpful
Answer :
›»› The volume of a cylinder is 6237 cm³.
›»› The curved surface area of a cylinder is 1188 cm².
›»› The total surface area of a cylinder is 1881 cm².
Given :
- Diameter of a cylinder = 21 cm.
- Height of a cylinder = 18 cm.
To Find :
- Volume of a cylinder = ?
- Curved surface area of a cylinder = ?
- Total surface of a cylinder = ?
Solution :
First we need to find the radius of a cylinder.
As we know that
→ Radius = Diameter ÷ 2
→ Radius = 21 ÷ 2
→ Radius = 10.5
The radius of a cylinder is 10.5 cm.
As we know that
→ Volume of cylinder = πr²h
→ Volume of cylinder = 22/7 * (10.5)² * 18
→ Volume of cylinder = 22/7 * 110.25 * 18
→ Volume of cylinder = 22/7 * 11025/100 * 18
→ Volume of cylinder = 22 * 1575/100 * 18
→ Volume of cylinder = 22 * 15.75 * 18
→ Volume of cylinder = 346.5 * 18
→ Volume of cylinder = 6237
Hence, The volume of a cylinder is 6237 cm³.
As we know that
→ CSA of cylinder = 2πrh
→ CSA of cylinder = 2 * 22/7 * 10.5 * 18
→ CSA of cylinder = 2 * 22 * 1.5 * 18
→ CSA of cylinder = 44 * 1.5 * 18
→ CSA of cylinder = 66 * 18
→ CSA of cylinder = 1188
Hence, The curved surface area of a cylinder is 1188 cm².
As we know that
→ TSA of cylinder = 2πr(r + h)
→ TSA of cylinder = 2 * 22/7 * 10.5(10.5 + 18)
→ TSA of cylinder = 2 * 22/7 * 10.5 * 28.5
→ TSA of cylinder = 2 * 22 * 1.5 * 28.5
→ TSA of cylinder = 44 * 1.5 * 28.5
→ TSA of cylinder = 66 * 28.5
→ TSA of cylinder = 1881