2014 · Q75
Bisectors of two adjacent angles A and B of a quadrilateral ABCD intersect each other at a point P. Which one of the following is correct?
Elementary MathematicsQuadrilaterals and Polygons
- A2∠APB = ∠C + ∠D
- B∠APB = ∠C + ∠D
- C∠APB = 180° − (∠A + ∠B)
- D∠APB = 180° − (∠C + ∠D)
Explanation
∠APB = 180° − (A+B)/2; with A + B + C + D = 360°, this equals (C + D)/2.