Question

Please help me on this question, it is a geometry question.

Answer 1

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

`m\angle B+m\angle D=180`

Since m < B = 72, then

`72+m\angle D=180`

Subtract 72 from both sides

`\begin{gathered} 72-72+m\angle D=180-72 \\ m\angle D=108 \end{gathered}`

The measure of angle ADC is 108 degrees

The answer is (3)