Question

quadrilateral ABCD is inscribed in circle O as shown below. which of the following would be used to find the measure of angle 3

Answer 1

180° -m∠1

Step-by-step explanation:

• Quadrilateral ABCD is a cyclic quadrilateral.

,

• The opposite angles of a cyclic quadrilateral add up to 180 degrees.

Therefore:

`\begin{gathered} m\angle3+m\angle1=180\degree \\ \implies m\angle3=180\degree-m\angle1 \end{gathered}`

Therefore, the second option would be used to find the measure of angle 3.