Answer:
∠ E = 135° , FG = 10
Explanation:
The opposite sides and angles of a parallelogram are congruent.
Consecutive angles are supplementary, that is sum to 180°
Then
3x - 15 + 7x - 5 = 180 , that is
10x - 20 = 180 ( add 20 to both sides )
10x = 200 ( divide both sides by 10 )
x = 20
then
∠ G = 7x - 5 = 7(20) - 5 = 140 - 5 = 135°
∠ E = ∠ G = 135°
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EF = HG ( substitute values )
3y = y + 8 ( subtract y from both sides )
2y = 8 ( divide both sides by 2 )
y = 4
then
EH = 2(y + 1) = 2(4 + 1) = 2 × 5 = 10
FG = EH = 10