# Answer of no. 2

We know that in a trapezium, side AB is parallel to side DC,

**So, angle A and angle D are complimentary......that is they add up to 180 degrees**

Also angle B and angle C are complimentary (just for your understanding)

angle A =

**x**degrees

angle D =

**(3x - 20)**degrees

Therefore :

x + 3x - 20 = 180

4x = 160

**x = 40 degrees**