Angles at a point and on a straight line

Explore the refreshed revision guide for GCSE Maths: Angles at a point and on a straight line, with step-by-step slideshows, quizzes, practice exam questions, and more!

around a point add up to 360°. This fact can be used to calculate missing angles.

Calculate angle \(a\).

\(a = 360^\circ - 60^\circ - 95^\circ - 105^\circ = 100^\circ\)

Angles on a straight line add up to 180°. This fact can also be used to calculate angles.

Calculate the angles \(b\) and \(c\).

\(b = 180^\circ - 30^\circ = 150^\circ\)

\(c = 180^\circ - 150^\circ = 30^\circ\)

Notice that vertically opposite angles are equal.

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