Look at the sector of the circle shown below. To calculate the length of the arc, we need to know what fraction of the circle is shown. To do this, we use the angle and compare it with 360˚.

GCSE Edexcel Circles, sectors and arcs - Edexcel Arc length The circumference of a circle is its outside edge, and is the same distance from the centre at every point along its length.

Auxiliary circles can help you solve problems that involve circles or arcs, such as finding the center, radius, tangent, or chord of a circle, or dividing a circle into equal parts.

Blackburn's formula does this by sketching the arc of your car's turning capability into a full circle, then using the center of the circle to create the right-angle triangles Pythagoras loved ...