Question

In a quadrilateral ABCD, angle A = 120°, angle B = 60° and angle C =
70°. Find angle D.​

Answer 1

1. sum of quadrilateral is 360 degree.
2. a+b+c+d =360
3. 120+60+70+d=360
4. 250+d=360
5. d=360-250
6. d=110 degree

the answer of angle d is 110 degree.