Question

If ABCD is a cyclic quadrilateral, what will be the value of $x$ (in degrees)?

• A. 120°
• B. 90°
• C. 100°
• D. None of these

Answer 1

The correct option is C

100°

The sum of opposite angles of the cyclic quadrilateral is ${180}^{\circ }$.

$\angle DAB+\angle DCB={180}^{\circ }$

${80}^{\circ }+x={180}^{\circ }$

$\Rightarrow x={100}^{\circ }$