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Circle Calculator
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Circle Calculator is an online tool used to find the diameter, area and circumference of a circle.

Circle is defined as the set of points that is at an equal distant from the centre of the circle. The circle can drawn by a complete revolution of 360° from a single point called the centre without changing the radius. The units of length that will not affect the calculations. The unit remains same for diameter and circumference of a circle, only it defer for area of a circle (i.e. from unit to unit square). Any other base unit can be substituted.

## Step by Step Calculation

Step 1 :

Circle Formula's

Diameter of a Circle

d = 2r

Where d = diameter and r = radius

Area of a Circle

A = $\pi$r2

Where A = area, r = radius and $\pi$ value = 3.142

Circumference of a Circle

C = 2$\pi$r

Where C = circumference, r = radius and $\pi$ value = 3.142

Step 2 :

Put the values in the above formula's and solve it further.

## Example Problems

1. ### The radius of a circle is 6 cm. Figure the diameter, area and circumference of that circle?

Step 1 :

Given: r = 6 cm

Diameter of a Circle

d = 2r

Where d = diameter and r = radius

Area of a Circle

A = $\pi$r2

Where A = area, r = radius and $\pi$ value = 3.142

Circumference of a Circle

C = 2$\pi$r

Where C = circumference, r = radius and $\pi$ value = 3.142

Step 2 :

Put the values in the above formula's and solve it further.

Diameter of a Circle

d = 2 * 6

= 12 cm

Area of a Circle

A = $\pi$62

A = 3.142 * 36 cm2

A = 113.09 cm2

Circumference of a Circle

C = 2$\pi$6

C = 2 * 3.142 * 6

C = 37.69 cm

Diameter of the Circle = 12 cm

Area of Circle = 113.09 cm2

Circumference of a Circle = 37.69 cm

2. ### The radius of a circle is 11 cm. Figure the diameter, area and circumference of that circle?

Step 1 :

Given: r = 11 cm

Diameter of a Circle

d = 2r

Where d = diameter and r = radius

Area of a Circle

A = $\pi$r2

Where A = area, r = radius and $\pi$ value = 3.142

Circumference of a Circle

C = 2$\pi$r

Where C = circumference, r = radius and $\pi$ value = 3.142

Step 2 :

Put the values in the above formula's and solve it further.

Diameter of a Circle

d = 2 * 11

= 22 cm

Area of a Circle

A = $\pi$112

A = 3.142 * 121 cm2

A = 380.13 cm2

Circumference of a Circle

C = 2$\pi$11

C = 2 * 3.142 * 11

C = 69.11 cm

Diameter of the Circle = 22 cm

Area of Circle = 380.13 cm2

Circumference of a Circle = 69.11 cm

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