For a cyclic quadrilateral The opposite angles are supplementary (meaning they sum up to 180 °) I.e (x +20) ° + 3x ° =180 ° 20 + 4x = 180 4x=180 - 20 4x = 160 Divide through by 4 x = 40 °
Angle at point A (2x + 38) = (2(40) + 38) = 118 °
Angle at point B 3x = 3(40) = 120 °
Angle at point D x + 20 = 40 + 20 = 60 °
Angle at point C The total angle in a quadrilateral is 360 ° I.e 118 + 120 + 298 +
