# How to Calculate and Solve for the Perimeter or Circumference, Radius and Diameter of a Circle | The Calculator Encyclopedia

The image above is a circle. To calculate the perimeter or circumference of a circle, one essential parameter is needed and this parameter is the radius of a circleÂ (r). You can also use theÂ diameter of a circleÂ to compute the area of a circle (d).

The formula for calculating the perimeter or circumference of a circle is:

P = 2Ï€r

Where:

P = Perimeter or Circumference of a circle
r = Radius of a circle

Letâ€™s solve an example:
Find the perimeter or circumference of a circle where the radius of a circle is 8 cm.

This implies that;
r = Radius of a circle = 8 cm

P = 2Ï€r
P = 2 x 3.142 x 8
That is, P = 50.265

Therefore, the perimeter or circumferenceÂ of a circleÂ isÂ 50.265 cm.

### Calculating the Area of a Circle using the Diameter of a Circle.

The formula is P =Â Ï€d

Where:

P = Perimeter or Circumference of a circle
d = Diameter of a circle

Letâ€™s solve an example:
Find the perimeter or circumference of a circle where the diameter of a circle is 10 cm.

This implies that;
d = Diameter of a circle = 10 cm

P =Â Ï€d
P = 3.142 x 10
So, P = 31.42

Therefore, the perimeter or circumference of a circle with diameter is 31.42 cm.

### How to Calculate Radius of a Circle when Perimeter or Circumference of the Circle is Given

r = P / 2Ï€

where;

r = Radius of a circle
P = Perimeter or Circumference of a circle

Letâ€™s solve an example:
Find the radius of a circle where the perimeter or circumference of the circle is 16 cm.

This implies that;
P = Perimeter or Circumference of the circle = 16 cm

r = P / 2Ï€
r = 16 / 6.284
Then, r = 2.55

Therefore, the radius of the circle is 2.55 cm.

### How to Calculate Diameter of a Circle when Perimeter or Circumference of the Circle is Given

d = P / Ï€

where;

d = Diameter of a circle
P = Perimeter or Circumference of a circle

Letâ€™s solve an example;
Find the diameter of a circle where the perimeter or circumference of the circle is 20 cm

This implies that;
P = Perimeter or Circumference of the circle = 20 cm

d = P / Ï€
d = 20 / Ï€
So, d = 6.365

Therefore, the diameter of the circle is 6.365 cm.

### How to Calculate and Solve for the Perimeter or Circumference, Radius and Diameter of a Circle Using Nickzom Calculator

Nickzom Calculator â€“Â The Calculator EncyclopediaÂ is capable of calculating the perimeter or circumference of a circle.

To get the answer and workings of the perimeter or circumference of a circle using theÂ Nickzom Calculator â€“ The Calculator Encyclopedia.Â First, you need to obtain the app.

You can get this app via any of these means:

To get access to theÂ professionalÂ version via web, you need toÂ registerÂ andÂ subscribeÂ forÂ NGN 1,500Â perÂ annumÂ to have utter access to all functionalities.
You can also try theÂ demoÂ version viaÂ https://www.nickzom.org/calculator