Circumference of a circle

obwod kola

The formula for the circumference of the circle

O = 2 · Pi · r

Legend:

O – circumference of a circle

Pi – number pi = 3,1415

r – radius of the circle

 

Sample task:

Calculate the circumference of a circle with a radius 4 cm.

O = 2 · Pi · r

O = 2 · 3,1415· 4 cm

O = 25,132 cm











wheel circumference pattern
circle circumference pattern

 

 

The formula for the circumference of the circle

O = Pi · d

Legend:

O – circumference of a circle

Pi – number pi = 3,1415

d – Diameter of a circle

 

Sample task:

Calculate the circumference of the circle in diameter 9 cm.

O = Pi · d

O = 3,1415· 9 cm

O = 28,2735 cm

 

Circumference Calculator ⇓

Task patterns