Circles

Arc Angle



$$θ = {360°l}/{2πr}$$

Arc Length



$$Arc Length(l) = {θ°2πr}/{360°}$$

Sector Area



$$Sector Area = {θ°πr^2}/{360°}$$

Segment



$$Segment = Sector - Area_{ΔABC}$$

Chord Length



$$Chord Length(AB) = √{(AC)^2+(BC)^2-2abcos(θ)}$$