Perimeter or circumference of a circle

Perimeter of a Circle

The perimeter of a circle is the whole length of a circle. It is the total length that is measured around and outside the circle. Perimeter of a circle is also referred as Circumference of a circle.

The length of the thread that winds around the circle exactly once, gives the perimeter of the circle.

The perimeter of a circle depends on its radius of the circle.

If ‘ r ‘ is the radius of a circle, then its perimeter “ P “ is given by the formula

P = 2πr

If ‘ d ‘ is the diameter of a circle, then its perimeter “ P “ is given by the formula

P = πd

Perimeter of a Half Circle

The diameter divides the circle into two equal arcs called semi circle or half circle.

We know that, If ‘ r ‘ is the radius of a circle, then its perimeter “ P “ is given by the formula

P = 2πr

Therefore, Perimeter of a semi circular arc AB = π * r units.

If ‘ d ‘ is the diameter of a circle, then its perimeter “ P “ is given by the formula

P = π * d

Therefore, Perimeter of the semi circular arc AB in terms of diameter is (d2) units.

Perimeter of a Half Circle Formula

If ‘ r ‘ is the radius of a circle, then the perimeter “ P “ of the half circle is given by the formula

P = πr + 2r

If ‘ d ‘ is the diameter of a circle, then the perimeter “ P “ is the half circle is given by the formula

P = (d2) + d