All angles in triangle inside add up to 180
so
the angles are y, 79,37
therefor
y+79+37=180
solvde for y
y+79+37=180
add
y+116=180
subtract 116 from ot hsides
y=64
angle y=64 degrees
3 tens is 3 * 10 = 30
9 ones is 9 * 1 = 9
30 + 9 = 39
Answer: 39
Step-by-step explanation:

Unfortunately I do not know the rectangle you are speaking of, if you could provide the rectangle I would be happy to help.
X= 3 to x = 4 has a greater rate of change