Answer:
Presumably the first graph solely based on its shape.
Where is the pic of the angles to measure ? I would help
You
We can use trigonometry. The cosine of 15 will be the side adjacent to the 15-degree side (the one we are looking for) divided by 20, the hypotenuse. As cos(15) is about .966, we get 19.32 as the side we are looking for.