WAEC Mathematics 2017 Objective — Question 21

Question 21 of 50 from the West African Examinations Council (WAEC) Mathematics 2017 Objective paper, with the correct answer and a full explanation.

The diagram above shows a circle centre O. If ∠ZYW=33°, find ∠ZWX.

A. A. 33°
B. B. 57°Correct
C. C. 90°
D. D. 100°

Explanation

Join Y to Z (construction). ∠WYZ=90° (angle at centre is 2x angle at circumference, WZ is a diameter making this a right angle). So ∠ZYX=33+90=123°. Since ∠ZYX+∠ZWX=180° (opposite angles of a cyclic quadrilateral are supplementary): ∠ZWX=180-123=57°.

Sign up free to unlock

Score tracking
Practice history
Saved questions
Progress dashboard
Personalized sessions
Weak-topic breakdown

…and/or go further with premium services and No Ads.

Create free account

More questions from Mathematics 2017 Objective More Mathematics past papers