Question

Find the circumference of a circle whose diameter is3.5 cm

Answer 1

Answer:

C=2πr

Step-by-step explanation:

C=2πr

Answer 2

Given :

• Diameter of a circle = 3.5 cm

To find :

• Circumference of a circle

Knowledge required :-

• Formula to calculate radius od a circle :-

⠀⠀⠀⠀⠀Radius = Diameter/2

• Formula to calculate circumference of a circle :-

⠀⠀⠀⠀⠀Circumference = 2πr

[Where : Take π = 22/7 and r is the radius of the circle.]

Solution :

Firstly, we will find the radius of the circle.

⠀⠀⠀⇒ Radius = Diameter/2

⠀⠀⠀⇒ Radius = 3.5/2

⠀⠀⠀⇒ Radius = 35/20

⠀⠀⠀⇒ Radius = 7/4

⠀⠀⠀⇒ Radius = 1.75

Radius of the circle = 1.75 cm

Now, substitute the value of the radius of the circle in the formula of circumference of the circle to find it's value.

⠀⠀⠀⇒ Circumference = 2πr

⠀⠀⠀⇒ Circumference = 2 × 22/7 × 1.75

⠀⠀⠀⇒ Circumference = 77/7

⠀⠀⠀⇒ Circumference = 11

Circumference of the circle = 11 cm

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Some related formulae :-

• Area of circle = πr²
• Diameter = 2 × Radius
• Surface area of sphere = 4πr²
• Volume of cylinder = πr²h
• Volume of cone = 1/3 πr²h
• Curved surface area of cone = πrl
• Total surface area of cone = πrl + πr²h
• Total surface area of cylinder = 2πrh + 2πr²