Answer:
60 feet
Explanation:
The slope of the roof is the vertical distance over the horizontal distance. This means for very 7 feet vertical the roof spreads out 2 feet horizontal. So if the roof is 210 feet vertical, then the horizontal will be _____.
This is found by setting up a proportionand solving for the unknown distance.

7y = 2*210
7y = 420
y = 60
The horizontal distance will be 60 feet.