So, the first blank is for what kind of angle it is: acute, obtuse, reflex, straight, or right. The second blank is for what the measure of the angle is. You can find that out by looking at the protractor. It should tell you what the measure of the angle is. You can read the protractor by looking at the numbers. The numbers are the degrees of incline the angle measures, which is what you're looking for.
The answer is 6 because you have to first find the answer for (4*2) and (5-3)
2 * plane speed in still air = 289mph + 257mph = 546
plane speed in still air = 273 mph
plane speed in still air + wind speed = 289
273 + wind speed = 289
Therefore, wind speed = 16 mph