Home › concepts › circle theorems

Circle Theorems Explained

Circle theorems are fundamental geometric principles about circles, angles, chords, tangents, and arcs. These theorems help solve problems related to angle

✓ 100% Free ✓ No Login Needed ✓ NCERT / CBSE Aligned ✓ Download as PDF

TL;DR: Circle theorems are fundamental geometric principles about circles, angles, chords, tangents, and arcs. These theorems help solve problems related to…

Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated Jul 23, 2026

🤖 Stuck on any question? Ask Syllab's free AI Tutor for a step-by-step explanation — instant, unlimited, no login.

Circle Theorems: Circle theorems are fundamental geometric principles about circles, angles, chords, tangents, and arcs. These theorems help solve problems related to angle

Circle Theorems Explained Simply

Circle theorems are fundamental geometric principles about circles, angles, chords, tangents, and arcs. These theorems help solve problems related to angle This is a key Mathematics concept for 10.

Frequently Asked Questions

Why is the angle in a semicircle always 90°?

A semicircle has a central angle of 180°. By inscribed angle theorem, any inscribed angle is half the central angle. Therefore, inscribed angle = 180°/2 = 90°.

What is the alternate segment theorem and when is it used?

The alternate segment theorem states: The angle between a tangent and a chord equals the inscribed angle in the alternate segment. It is used when you have a tangent and chord meeting at a point on the circle.

How are tangent-chord angles different from inscribed angles?

Both equal half the arc they subtend, but are measured differently. Inscribed angle is measured from two points on circle. Tangent-chord angle is measured between a tangent line and a chord at their point of intersection on the circle.

Related Mathematics Concepts

  • Pythagoras Theorem Explained
  • Quadratic Equations Explained
  • Trigonometry: Ratios and Identities Explained
  • Probability Explained
  • Polynomials Explained
  • Linear Equations in Two Variables Explained

Browse all concepts →

Explore:

  • Syllabus
  • Practice
  • Mock Tests
  • NCERT Solutions
  • Coding
  • GK Quiz
  • Career Predictor
  • AI Tutor
  • Live Quiz
  • Doubt Solver
  • Microlearning
  • Free Alternatives
  • Kids Zone
  • Study Room
  • Calculators
  • Worksheets

Syllab.in — Free learning for Indian students, Class 1–12