Circles Class 10 Notes Maths: Chapter 10

Basic Concepts-01


  1. tangent to a circle is a line that touches the circle at only one point. There is only one tangent at a point on a circle.
  2. From a point lying outside a circle, two and only two tangents can be drawn to it.
  3. The lengths of the two tangents drawn from an external point to a circle are equal.
  4. A tangent to a circle is perpendicular to the radius through the point of contact.
  5. A line whichintersects a circle at two distinct points is called secant of the circle.
  6. Alternative Segment Theorem : If a chord is drawn through the point of contact of a tangent to a circle, then the angles made by the chord with the tangent are respectively equal to the angles subtended by the chord in the alternate segments.