Question 145657
The interior angles of the parallelogram equal 360 degrees. 
Also, the oppposite angles are equal. 
Angle A = Angle C 
Angle B = Angle D
{{{A + B + C + D = 360}}} The sum of the angles is 360.
{{{A+D+A+D=360}}} Substitute for B and C.
{{{2A+2D=360}}} Simplify.
{{{A+D=180}}}Divide by 2.
{{{5x+30+x=180}}}Substitute for A and D.
{{{6x=150}}}Simplify.
{{{x=25}}}Solve for x. 
{{{5x+30=155}}}Solve for A and C.
Angle A = Angle C = 155 degrees
Angle B = Angle D = 25 degrees