When the 4 vertices of a quadrilateral lie on the circle, that means
The quadrilateral is a cyclic
In the cyclic quadrilateral, every 2 opposite angles are supplementary (their sum is 180 degrees)
Since ABCD is a cyclic quadrilateral, then
[tex]m\angle B+m\angle D=180[/tex]
Since m < B = 72, then
[tex]72+m\angle D=180[/tex]
Subtract 72 from both sides
[tex]\begin{gathered} 72-72+m\angle D=180-72 \\ m\angle D=108 \end{gathered}[/tex]
The measure of angle ADC is 108 degrees
The answer is (3)
