Question

question 7 of 10
in the diagram below, ⊙o is circumscribed about quadrilateral defg. what is the value of x?
a. 130
b. 70
c. 80
d. 110

Explanation:

Step1: Use cyclic quadrilateral property

Opposite angles sum to $180^\circ$. So $\angle G + \angle E = 180^\circ$

Step2: Substitute angle values

$120^\circ + (x - 10^\circ) = 180^\circ$

Step3: Simplify and solve for $x$

$x + 110^\circ = 180^\circ$
$x = 180^\circ - 110^\circ = 70^\circ$

Answer:

B. 70