GCSE Maths (Edexcel)

435 videos | 33 hours

Twin Angles at Circumference

Please subscribe to watch this video.

This, and all other videos, are included in our premium subscriptions.

Premium accounts get access to all videos.

Geometry and Measures Properties and Constructions

Twin Angles at Circumference

1:53 More Circle Theorems
Spec G10
Previous Triangle from a Diameter Next Front & Side Elevations
  • The angles of the circumference subtended by the same arc are equal
  • An arc is a portion of a circle's circumference
  • An angle subtended by an arc is formed by two straight lines originating from the ends of the arc
  • The angles at the center of a circle is twice the angle at the circumference subtended by the same arc
  • By extending two radii from points A and B to the center of the circle, a new angle at the center subtended by the same arc is created
  • The angle at the center must equal twice the angle at the circumference
  • The only way for this to be true is if the angles at the circumference are equal
  • This circle theorem needs to be known and able to be proven

Please subscribe to access these revision notes.

This, and all other video notes, are included in our premium subscriptions.

Premium accounts get access to all videos and revision notes.