MihsabaHow to use
A circular sector is the part of a disk bounded by two radii and their arc. From radius and central angle you can calculate sector area, arc length, chord length and the corresponding circular-segment area.
- Enter the radius and choose a length unit.
- Enter the angle and choose degrees or radians.
- Review sector area, arc, chord, sector perimeter and segment area.
How it is calculated
s=rθ; A=½r²θ; c=2r·sin(θ/2)
Example
For radius 10 and angle 90°: arc length = 5π ≈ 15.708 and sector area = 25π ≈ 78.540.
Important notes
The compact formulas s=rθ and A=½r²θ require radians; degree input is converted automatically. At 360°, the sector boundary is the circle circumference because the two radial sides coincide.
Frequently asked questions
Can I enter radians?
Yes. Choose radians instead of degrees.
What is the difference between a sector and a segment?
A sector is bounded by two radii and an arc; a segment is bounded by a chord and the arc.
Is chord length the same as arc length?
No. The chord is straight while the arc is curved.
Is this calculator free?
Yes. It is free to use and requires no account.