All Circle Formulas

About All Circle Formulas

Let us first define a circle before studying all of the circle formulas. 

Let us first define a circle before studying all of the circle formulas. A circle is defined as a group of points in a plane that are all at the same distance from a fixed point. The fixed point is known as the circle's centre. The radius of a circle is the distance between its centre and its perimeter. Let's look at some examples of circle formulas that have been solved.What Are All Circle Formulas?

All circle formulas can be used to compute parameters such as area, circumference, and radius of a circle. Different circle formulas for calculating various parameters of a given circle are as follows:

Diameter of Circle, D = 2r

Circumference of Circle, C = 2 π r

Area of a Circle, A = π r2

Where r is radius of the circle

d is diameter of the circle

c is circumference of the circle

All Circle Formulas in One Place The collection of all circle formulas for easy calculations for a circle with radius 'r' is provided below.

Parameters Circle Formulas
Diameter of a circle formula D = 2 r
Circumference of a circle formula C = 2 π r
Area of a circle formula A = π r2

Solved Example of Circle formulas 

Example 1: Calculate the size of a circular park with a radius of 200 metres.

Solution:

To locate A park area.

Given: Radius of park = 200 m

Using area of a circle formula, we have

Area of a Circle = π r2

= π × 2002

= π × 40000

Example 2: Determine the radius of a circle with a circumference of 100 in using the perimeter of a circle formula.

Solution:

To find: Circular radius

Given: Circumference = 100 in using perimeter of a circle formula,

The perimeter of the circle or circumference = 2 π r

2 π r = 100

2 × 22/7 × r = 100

r = 100 × 7 / 44

r = 15.909 inches

Answer: The circle's radius = 15.909 in

Example 3: A circle's radius is 8 inches. Calculate the circumference of the circle using the circle formula.

Solution:

Circumference of the circle

Given: r = 8in

The perimeter of circle = 2 π r

C = 2 × (22/7) × (8)

Answer: The circumference of a circle is 50.28 inches.

What Is the Perimeter a Semi-Circle Formula?

Because the circumference of a semi-circle is half that of a full circle, the formula is 1/2 (2π r) = π r units.

Get the List of Maths formulas. 

Find a pdf of the list of circle formulas

All Circle Formulas
All Circle Formulas

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Frequently Asked Questions on All Circle Formulas

While using the circle formul you will find the diameter (D) in the formula, to use the diameter of a circle formula is defined as twice a radius.
Therefore, 
D = 2r, where r is the radius of a circle.

The perimeter of the circle formula is =2 π r
where 'r' is radius and π is constant with value (pie=3.14 or 22/7).

As you know the circumference of the circle formula is = 2 π r. 
If we know the value of the circumference of the circle, substituting the value in the formula we can calculate the radius, 'r'.
r = (circumference of circle)/ 2 π.