Step-by-step explanation:
It is 28°
Because both triangles FED and ABC are right (converse of pythagorean theorem)
Also the lengths of the side of the triangle ABC is double the lengths of the side of the other triangle
You calculate the measure of the angle ∠A in triangle ABC which is 28° (by calculation)
This will also be the measure of angle D
I'm not sure if it is right but hopefully it will help you.
