In a parallelogram ABCD  angle A is 3x-10 degree and angle B is 5x+30 degree.Find x and hence find all the angles of the parallelogram.

Value of x-
3x-10+5x+30=180(sum of the adjacent angles of a parallelogram is equal to 180 degree)
=>8x+20=180
=>8x=180-20
=>8x=160
=>x=160/8
=>x=20
Therefore, 3x-10=(3*20)-10
                           =50
                  5x+30=(5*20)+30
                            =130
Therefore, angle A=50 degree
                  angle B=130 degree
Since opposite angles of a parallelogram are equal,
Therefore, angle C=50 degree(opposite to angle A)
                  angle D=130 degree(opposite to angle B)