Arches & cut lines

Circle Chord & Segment Calculator

Turn a radius plus angle, chord, or sagitta into the full geometry of a minor circular segment. Useful for arches, layouts, fabrication and curve checks.

FreeNo sign-inInstant results
INPUT

Define the minor segment

Use an angle, chord or sagitta with the radius.

Known pair
Angle unit
RESULT

Calculated instantly

Chord length10 cm
Sagitta1.3397 cm
Central angle60°
Arc length10.472 cm
Minor segment area9.0586 cm²

The relationship

Formula

c = 2r sin(θ÷2) · h = r(1 − cos(θ÷2)) · A = ½r²(θ − sin θ)

For a radius of 10 cm and an angle of 60°: chord = 10 cm, sagitta ≈ 1.3397 cm, and minor segment area ≈ 9.0586 cm².

Straight answers

Common questions

What is a chord compared with an arc?

A chord is a straight line between two points on a circle. The arc is the curved part of the circumference between those points.

Can I calculate chord length without an angle?

Yes. A radius plus a valid sagitta is enough to derive the angle and chord length.

What is the difference between minor and major segments?

The minor segment uses the shorter arc and is at most a semicircle. The major segment is the remaining larger part of the circle.