Sector Area Calculator

Sector area calculator calculates the area of a sector of a circle by knowing its radius or diameter, central angle, or arc length.

Sector Area Formula

1. Knowing the radius and angle for a sector,

    the sector area formula is

    A = πr²(θ/360)

    where
    r = radius.
    θ = degrees.

    Or

    A = r² x θ/2
    where θ = radians.

2. Knowing the arc length and angles,

    the sector area formula is

    A = L²/θ x 2

    where
    θ = radians.
    L = Arc Length.

3. Knowing the arc length and radius,

    the sector area formula is

    A = L x r / 2

    where
    L = Arc Length.
    r = radius.

Quadrant Area Formula

The Quadrant area formula is

A = πr²/4

where
r = radius.

Quadrant is 1/4 of a circle, therefore a circle area divided by 4 will get a quadrant area.


For example, if a quadrant with a radius of 10, to calculate its area step by step,

A = πr²/4
  = 3.1415 x 10 x 10/4