Assuming the distribution is continuous, you have

If instead the distribution is discrete, the value will depend on how the interval of number between 1 and 29 are chosen - are they integers? evenly spaced rationals? etc
X + y = 180
x = 4y
Plug that in and you get: 4y + y = 180
5y = 180
y = 36
If you want the larger angle, simply plug in y to x = 4y
So: x = 4(36) = 144
The smaller angle is 36 degrees, and the larger angle is 144 degrees.
See the attached picture.
what figure or fraction can you show us please