SOLUTION: ABCD is a parrellelogram in which one angle is 120 . Find other three angles?

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Question 1085821: ABCD is a parrellelogram in which one angle is 120 . Find other three angles?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

A parallelogram is quadrilateral comprised of two pairs of parallel lines.
Opposite angles are congruent.

if ∠ A=120°, then ∠ C=120° too since they are opposite angles
same is with ∠ B and ∠ D;∠ B=D
since the sum of all angles is 360°, we have
∠ 120%2BB%2B120%2BD=360°
∠ B%2BB=360-240°
∠ 2B=120°
∠ B=60° =>∠ D=60°