NumericalEasy1 mark
3(a)
In the figure given below, O is the centre of the circle and AB is a diameter. If AC = BD and ∠AOC = 72° . Find:
∠BAD
Topic: Circle theorems
Previous-year question practice database
Answer
Exam answer
Given:
AC = BD
Equal chords of the same circle subtend equal angles at the circumference.
Therefore:
∠ABC = ∠BAD
From part (i):
∠ABC = 36°
Hence:
Answer:
∠BAD = 36°.
Explanation
Chords AC and BD are equal, so they subtend equal angles at the circumference. Since ∠ABC stands on chord AC and ∠BAD stands on chord BD, the two angles are equal.