हिन्दी में पढ़ेंHome › Formulas › Geometry › Circles
Circles formulas
18 formulas for Circles, from the Geometry section of the Quantix formula library. Tap 🧮 next to a formula to solve it for any variable with step-by-step working.
| Name | Formula | Note |
|---|---|---|
| Circumference | C = 2πr = πd 🧮 Solve step by step | |
| Area | A = πr² 🧮 Solve step by step | |
| Arc length | l = (θ/360°) × 2πr | |
| Sector area | (θ/360°) × πr² | |
| Segment area | r²/2 (θ·π/180° − sin θ) | |
| Angle at centre | = 2 × angle at circumference on the same arc | |
| Angle in a semicircle | 90° | |
| Angles in the same segment | equal | |
| Tangent ⊥ radius | at the point of contact | |
| Tangents from an external point | equal in length | |
| Tangent length | √(d² − r²) | d distance from centre |
| Chord from centre | perpendicular from centre bisects a chord | |
| Chord length | 2√(r² − d²) | |
| Intersecting chords | AE · EB = CE · ED | |
| Secant–tangent | PT² = PA · PB | |
| Alternate segment theorem | tangent–chord angle = angle in the alternate segment | |
| Direct common tangent | √(d² − (r₁ − r₂)²) | |
| Transverse common tangent | √(d² − (r₁ + r₂)²) |
Open in the interactive Formula Library