ABCD is a cyclic quadrilateral, CD is the diameter of the circle.
| ABCD is a cyclic quadrilateral, CD is the diameter of the circle. If ∠ BCD = 60°, the measure of ∠BAD is
A. 140°
B. 80°
C. 60°
D. 120°
Please scroll down to see the correct answer and solution guide.
Right Answer is: D
SOLUTION
ABCD is a cyclic quadrilateral.
CD is the diameter of the circle.
We know that in a cyclic quadrilateral, the summation of opposite angles will be 180°.
∠ BCD = 60°
We can write,
∠ BCD + ∠ BAD = 180°
⇒ ∠ BAD = 180° - 60° = 120°
∴ The measure of ∠BAD is 120°.