What is the measure of angle D?

Answer:
52
Step-by-step explanation:
Since the sum of interior angles in a quadrilateral is 360°, you have to subrtact all those numbers from 360° in order to get angle D. What I mean is:
360 - (128+126+54)
360 - 308
52
Answer:
52°
Step-by-step explanation:
The trapezoid is a closed figure, meaning all the angles must equal 360°.
1. Set up the equation
128° + 126° + 54° + ∠D = 360°
2. Solve for ∠D
360 - 128- 126- 54 = 52
∠D = 52°
You can also solve this by knowing that in a trapezoid:
∠A + ∠D = 180° and ∠B + ∠C = 180°
1. Set up the equation
128 + ∠D = 180°
2. Solve
180 - 128 = 52
∠D = 52°