SOLUTION: In parallelogram ABCD if angle A = 5x+30, and m angle D = x, find m angle C.

Algebra ->  Parallelograms -> SOLUTION: In parallelogram ABCD if angle A = 5x+30, and m angle D = x, find m angle C.      Log On


   

Question 145657: In parallelogram ABCD if angle A = 5x+30, and m angle D = x, find m angle C.
Answer by Fombitz(32388) About Me  (Show Source):
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The interior angles of the parallelogram equal 360 degrees.
Also, the oppposite angles are equal.
Angle A = Angle C
Angle B = Angle D
A+%2B+B+%2B+C+%2B+D+=+360 The sum of the angles is 360.
A%2BD%2BA%2BD=360 Substitute for B and C.
2A%2B2D=360 Simplify.
A%2BD=180Divide by 2.
5x%2B30%2Bx=180Substitute for A and D.
6x=150Simplify.
x=25Solve for x.
5x%2B30=155Solve for A and C.
Angle A = Angle C = 155 degrees
Angle B = Angle D = 25 degrees