Question

in the diagram below, ⊙o is circumscribed about quadrilateral abcd. what is the value of x? a. 100 b. 21 c. 57 d. 15

Explanation:

Step1: Recall cyclic quadrilateral property

Opposite angles sum to $180^\circ$.

Step2: Set up angle equation

$5x + 75 = 180$

Step3: Solve for $x$

$5x = 180 - 75$
$5x = 105$
$x = \frac{105}{5}$

Answer:

D. 15