GCSE Maths (Edexcel)

435 videos | 33 hours

Circumference from Radius

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 Mensuration and Calculation

Circumference from Radius

2:15 Circumference of a Circle
Spec G17
Previous Circumference of a Circle & Pi Next Area of a Circle
  • The formula for the circumference of a circle can be written as C = 2��R
  • The circumference of any circle is equal to its diameter multiplied by pi (��)
  • The formula for the circumference of a circle in terms of the radius is C = ��D
  • The diameter is twice the length of the radius (D = 2R)
  • To calculate the radius of a circle, rearrange the equation for circumference to make the radius the subject: R = C / 2��
  • Plug in the given values to calculate the radius
  • The radius can be calculated as R = 5 / (2��), which equals 0.796 meters to 3 significant figures (3SF)

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.