# Semicircle

## Semicircle

One half of a circle.

• Every chord that passes through the centre of a circle divides the circle into two semicircles.
• The term “semicircle” is the synonym of “hemicycle.”

### Formula

The formula to calculate the perimeter P of a semicircle is: $$P = πr$$, where r is the radius of the circle.

### Example

In simple terms, a semicircle is a construction that has the shape of one half of a circle, such as a theatre or a basilica. This shape was used in some parliaments to promote cooperation among political groups, particularly in democratic systems.