Question

Two opposite angles of parallelogram are (150-3x)and (2x-50).find the measure of all four sides

Answer 1

We know opposite angles are equal in a parallelogram. So,
150-3x=2x-50
or, 200=5x
or, x=200/5=40 degrees

hence the angles are 150-(3*40)=30 degrees 

also adjacent sides are supplementary, so 
another pair of angles are 180-30 each
that is 150 degrees each.

therefore the required answer is 30,150,30,150.

hope it helps. :)

Answer 2

We know opposite angles are equal in a parallelogram. So,

150-3x=2x-50

or, 200=5x

or, x=200/5=40 degrees

hence the angles are 150-(3*40)=30 degrees

also adjacent sides are supplementary, so

another pair of angles are 180-30 each

that is 150 degrees each.

therefore the required answer is 30,150,30,150.