is a cyclic quadrilateral and the sides and are produced to meet at . If and , then is equal to:
- A25^\circ
- B70^\circ
- C95^\circ
- D85^\circ
Solution & Step-by-step Explanation
In a cyclic quadrilateral, the exterior angle at any vertex is equal to the interior opposite angle.
Here, side is extended to , making an exterior angle at vertex .
The interior opposite angle to is .
Now, consider . The sum of angles in a triangle is :
Here, side is extended to , making an exterior angle at vertex .
The interior opposite angle to is .
Now, consider . The sum of angles in a triangle is :