Calculate the pitch of a roof from the rise and rune measurements.
Measure a horizontal distance (run) inward from the edge of the building either on top of the fascia board or below. Just make sure you measure the vertical height (rise) to the same as you did the run measurement, to the top of the fascia or the bottom.
The run measurement can be any length, it does not have to go to the centre. A longer measurement might make it a bit easier or more accurate.
You measured 10 feet in (horizontal) from the outside wall. At that point you measure the rise measurement perpendicular (at a right angle) to the run measurement. In this case it is 5 feet 10 inches.
10' = 120 inches 5'-10" = 70 inches
70 ÷ 120 = 0.5833333333333333 * 12 = 7 7 : 12 pitch
70 ÷ 120 = 0.5833333333333333 * 100 = 58.3 (rounded to one digit) grade of the roof = 58.3%
Arctan ( 0.583) = 30.2421853687 roof angle = 30.3° (rounded to one digit)