The formula for the circumference of a 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
The formula for the circumference of a 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