Convert a roof pitch of rise in 12 to the angle of the roof in degrees.
The roof pitch is the slope of a roof expressed as a numerical ratio of a rise in inches in a horizontal run of 12 inches.
With a 12:12 pitch, the roof rises 12 inches in a 12-inch horizontal run.
A 12 in 12 pitch = 45°
One could be inclined to assume that a 6 in 12 slope would equal half of that, 22.5°. But that would be a wrong assumption!
You are not halving the angle by reducing the rise this way.
A 6 in 12 pitch = 26.5651 degrees.