In the parallelogram shown in the image, the opposite angles are the same.
So, ∠D = ∠B (3x + 17 = 5x - 3)
Solve for x.
3x + 17 = 5x - 3
~Subtract 17 to both sides
3x + 17 - 17 = 5x - 3 - 17
~Simplify
3x = 5x - 20
~Subtract 5x to both sides
3x - 5x = 5x - 5x - 20
~Simplify
-2x = -20
~Divide -2 to both sides
-2x/-2 = -20/-2
~Simplify
x = 10
Substitute x with 10 for ∠B
5(10) - 3
50 - 3
47°
Parallelograms have adjacent angles which are supplementary.
So, ∠A + ∠B = 180°
We know that ∠B = 47°, so, solve for ∠A.
∠A + 47 = 180
∠A + 47 - 47 = 180 - 47
∠A = 133°
Therefore, the measure of ∠DAB is 133°
Best of Luck!
