Circle Sector, Segment, Chord and Arc Calculator
Scroll to the bottom for the Circle Calculator
Click here for the formulas used in this calculator.
Lines AO and OB are called radii.
Lines AC, BC and AB are called chords.
The angle ACB is an inscribed angle.
The angle AOB is a central angle.
The curved blue line AB is called an arc.
Line OE is the apothem and is the height of triangle AOB.
Line ED is the segment height
or the sagitta  a rarelyused term.


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The length of an arc equals
(Central Angle / 180°) •
π • r
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The yellow area that resembles
a "pizza slice" is a sector.
The area of a sector equals
(Angle AOB / 360°) •π • r²
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The green area (Circle Two) is a segment.
The area of a segment equals
Sector Area
Minus Triangle AOB Area
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Circle Calculator
