#5,
it says that the angle on top is 221, so you subtract that from 360,
360-221= the rest..... 139
Now in that 139, you can see that there is a triangle with a right angle. so you can subtract 90 degrees from 139
139-90= 49
49 is the number you use to solve the rest.
3x + 4x = 7x
so 7x = 49
and then you divide 7 from both sides to isolate x, and you get your answer