Circles:
The chapter 'Circles' carrying the weightage of 6 - 7 marks in the board examination. It covers the concepts like tangent to a circle, length of tangent from a point, tangent from an external point.
 
Most possible variation of question types that we can expect in board exam as per previous year question paper are discussed below.
 
Total marks 6 - 7 
Variation 1 Variation 2
  • 1 Sec A
  • 1 Sec B
  • 1 Sec C
Total marks=6
  • 1 Sec B
  • 1 Sec D
Total marks=7
 
To prepare well for the board examination, it is necesary to understand the following concepts clearly.
 
  • Tangent to a circle - Length of a tangent, one tangent form, radius perpendicualr to tangent at point of contact.
  • Number of tangents
  • Tangent from an external point.
Important Concept (Learning Outcomes) Expected Question Type Concept deat with
Tangent to a circle  Sec A, Sec B, Sec, Sec C
  1. Find the radius
  2. Find the length
  3. Find the angle
Tangent to a circle Sec D
Tangent from an external point Sec A, Sec B, Sec C, Sec D
  1. Find the length
  2. Find the angle
  3. Prove the following
 
Let us recall the concepts in circles:
Tangent: The tangent to a circle is perpendicular to the radius through the point of contact.
 
Theorem 1: The tangent at any point of a circle is perpendicular to the radius through the point of contact
 
Theorem 2: The length of the tangents drawn from an exterior point to a circle are equal.