Calculate the value of x

Angle AOB = 2x + 28. An angle at the circumference is half that at the centre, so angle ACB = x + 14. Opposite angles of a cyclic quadrilateral sum 180° , so ACB + ADB = 180. ADB is given as 3x - 70. This combines to x + 14 + 3x - 70 = 180, which simplifies to 4x = 236, so x = 59°. To check this is of a reasonable size this can be substituted into the formulas for AOB and ADB to give an obtuse angle, as expected.

EL
Answered by Eleanor L. Maths tutor

5456 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

A class of pupils were asked about how they travelled to school on a particular day. 1/6 of the pupils were driven to school in a car. 2/5 of the pupils took the bus. The rest of the pupils walked to school. Calculate the fraction of pupils who walk


Find the interval for which x^2 - 7x + 10 </= 0


How do I factorise a quadratic equation?


How do you check if a graph ever touches the x-axis?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning