Answer:
Explanation:
If a quadrilateral is inscribed in a circle with all four edges touching the circumference of the circle, then the opposite angles are supplementary. This means that the sum of the opposite angles is 180 degrees. Therefore,
Angle B + angle D = 180
Angle A + angle C = 180
3x + x + 20 = 180
4x = 180 - 20 = 160
x = 160/4
x = 40
Angle A = 2 × 40 + 78 = 158 degrees
Angle B = 3 × 40 = 120 degrees
Angle C = 180 - 158 = 22 degrees
Angle D = 40 + 20 = 60 degrees