Back to Class IX Mathematics
Classes IX & X Mathematics

Chapter 9: Circles

Standard NCERT & CBSE aligned study curriculum. Master concepts, track accuracy, revise weak areas, and challenge yourself with 9 customized practice modes.

Class Syllabus Selection

This topic is taught in multiple grades. Switch classes to see specific curriculum details:

Example 1

Subtended Angle calculation

An arc subtends an angle of 80 degrees at the center of a circle. What angle does it subtend at the circumference?
sin θcos θθ

Calculation Steps:

  1. 1Apply double angle theorem: θ_center = 2 * θ_boundary.
  2. 2Rearrange: θ_boundary = θ_center / 2.
  3. 3Calculation: 80 / 2 = 40 degrees.
Solution40 degrees