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 Calculator
Radius		or     Diameter
Angle	Degree Radian
Area

Arc Length
Angle	Degree Radian
Area

Arc Length
Radius		or     Diameter
Area

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

  =78.54