Arcs of a circle

Lessons

• Introduction
  a)

  Terms related to circles

  • Radius
  • Diameter
  • Circumference
  • Central angle
  • minor arc
  • major arc
  • Inscribed angle
  • Chord
  • perpendicular bisector
  • Tangent
  • point of tangency
  
  
  b)

  How to find the length of an arc?

  • by Central angle
  • by Proportion
  • by Using formula a = Θr

  
  
  
  

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• 1.
  Find the length of the arc in red.
  a)

  
  
  
  
  b)

  
  
  
  
  c)

  
  
  
  

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• 2.
  In the following circle, AD is diameter and BC $\bot$ EF, and the radius is 7. Find the measures of:
  
  a)

  $arc AB$
  
  
  b)

  $arc ABE$
  
  
  c)

  $arc AEC$
  
  
  d)

  $\angle BFD$
  
  

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• 3.
  On circle D, arcAB= 105°, arcBC= 140° and arcABC= 245°. Point E is on the circle D too and arcCE= 145°. Explain what E must be on ArcAB.

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