wheelchair ramp

Question

The maximum angle of a wheelchair ramp in new construction may not exceed 4.764º. If the door to a building is 5 feet above sidewalk level, how long must the ramp be in order to extend from sidewalk to door?

Answer 1

We can find the horizontal distance from the sidewalk to

the point 5 feet below the door.  This will give us the

length of two legs of a right triangle.

 

tan ∅ = opposite/adjacent

tan(4.764) = 5/x

x = 5/tan(4.764)

x = 60 ft

 

The two legs of the right triangle are 5 ft and 60 ft

 

Pythagorean Theorem says  a² + b² = c²

where c is the hypotenuse of a right triangle with

leg lengths a, b.  In this case, c is the length of the

inclined ramp.

 

5² + 60² = c²

25 + 3600 = c²

c = √3625

c ≅ 60.2 ft

 

The ramp, if the angle is at 4.764 degrees, is 60.2 ft long