[jyl]

6.0974 feet

Tan (29) = 6.0974/11

I guess I better make sure I understand the situation. You're building a ramp. The ramp meets the floor at a 29 degree angle, the floor is horizontal. The ramp is a straight line, so is the floor. If you hung a plumb bob off the raised end of the ramp it would touch the floor 11 feet from where the ramp meets the floor.