Question

D

.0
A
58d
B
A, B, C and D are points on a circle, centre O.
Angle ABC = 58°
Calculate the size of angle ADC.
(1 mark)
Diagram NOT
accurately drawn

Answer 1

∠ ADC = 122°

Explanation:

ABCD is a cyclic quadrilateral.

opposite angles in a cyclic quadrilateral sum to 180° , that is

∠ ADC + ∠ ABC = 180∠

∠ ADC + 58° = 180° ( subtract 58° from both sides )

∠ ADC = 122°