Answer:
10.4 feet.
Explanation:
Let l be the length of the ramp which is leaning against the building,
Given,
The ramp makes a 15 degree angle with the ground.
Also, the distance of one end of ramp from the base of the building = 10 feet,
A building is generally supposed to perpendicular the ground,
Hence, By making the diagram,
We get,
( Trigonometric ratio ),

Therefore, the ramp is approximately 10.4 feet long.