A library wishes to build an access ramp for wheelchairs. The main entrance of the library is 8 ft. above sidewalk level. If the architect recommends a grade (angle of elevation) of 6°, how long must the access ramp be?​

About 76.5 ft.

Step-by-step explanation:

Draw a diagram of a right triangle.  The shorter leg represents the height of the main entrance of the library, which is 8 ft.  The longer leg won't matter in this case.  The hypotenuse is what we're trying to find, so mark it as x.  We know there's a 6° angle of elevation, so the 30° angle of the triangle will be 6° in this case.  Now we have to use trig.  Think of Soh Cah Toa.  The 6° is opposite from 8 and the hypotenuse is x.  So, the equation to find x would be:

sin (6°) = 8/x

Multiply both sides by x

sin (6°) * x = 8

Divide both sides by sin (6°)

x = 8/sin (6°)

When putting it into a calculator, your answer should be 76.534, which rounds to 76.5 ft.

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step-by-step explanation: