Write True or False and justify your answer in each of the following: If A, B, C, D are four points such that , then D is the centre of the circle through A, B and C.
True
Solution:
Given, ∠BAC = 30° and ∠BDC = 60°
We know that,
The angle subtended at the centre by an arc is twice the angle subtended by it at any part of the circle.
Considering BC,
At centre,
At any other point on the circle,
Hence the above rule is justified.
Therefore the given statement is true.