Question

in cyclic square ABCD measure angle A +measure angle b = 150 and measure angle b + measure angle C = 190 find measure angle d

Answer 1

angle d =360- (150+190)
=360-340
=20°

Answer 2

a+b=150 b+c=190 a+2b+c=340 a+c=180 b=80and b+d=180 d=100