In a circle with centre

MATHEMATICS · Subjective · GCSE · Mathematics · Geometry and Measures · Geometry and Measures

Problem

O

, points

A

and

B

lie on the circumference. The measure of

\angle AOB

(5x-20)^{\circ}

. At a point

C

on the circumference, the angle subtended by arc

AB

(2x+5)^{\circ}

. Calculate the value of

x

and hence find the measures of

\angle AOB

and

\angle ACB