Geometry · Topic guide
Circles — Geometry
Reason about radii, chords, tangents, arcs, and angles to understand the relationships that define circles.
Practice more with MathNivoAndroid app coming soonExplore the idea here, then continue practicing in the Android app when available.
What you’ll learn
- Calculate arc length.
- Calculate arc measures.
- Understand central angles.
- Solve chord problems.
Explore the skills
Choose an idea below to read a worked example and try one question.
- Calculate arc lengthCalculate arc length.
- Calculate arc measuresCalculate arc measures.
- Understand central anglesUnderstand central angles.
- Solve chord problemsSolve chord problems.
- Radius, diameter, chord, secant, tangentRadius, diameter, chord, secant, tangent.
- Construct/understand triangle circumcircleConstruct/understand triangle circumcircle.
- Construct/understand triangle incircleConstruct/understand triangle incircle.
- Understand inscribed anglesUnderstand inscribed angles.
- Use cyclic quadrilateral propertiesUse cyclic quadrilateral properties.
- Calculate sector areaCalculate sector area.
- Solve tangent/chord angle problemsSolve tangent/chord angle problems.
- Understand radius-tangent perpendicularityUnderstand radius-tangent perpendicularity.