text: ## Book: RS Aggarwal - Mathematics
  
  ### Chapter: 12. Circles
  
  #### Subject: Maths - Class 10th
  
  ##### Q. No. 45 of Multiple Choice Questions (MCQ)
  
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  45
  ##### In the given figure, PA and PB are tangents to the given circle such that PA = 5 cm and ∠APB = 60°. The length of chord AB is
  
  In the given Figure,
  
  As PA and PB are tangents from common external point P, we have
  
  PA = PB
  
  [ tangents drawn from an external point are equal]
  
  PBA = PAB
  
  [ Angles opposite to equal sides are equal]
  
  Now,
  
  In APB, By Angle sum Property of triangle
  
  APB + PBA + PAB = 180°
  
  60° + PAB + PAB = 180°
  
  2 PAB = 120°
  
  PAB = 60°
  
  So, We have
  
  PBA = PAB = APB = 60°
  
  i.e. APB is an equilateral triangle
  
  so, we have
  
  PA = PB = AB = 5 cm [ As PA = 5 cm ]
  
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