Asked by anna

The grade of a road is 7%. What angle does the road make with the horizontal?


I'm confused!! What is the grade of a road? Thanks for the help!
Answered by drwls
The "grade" is the tangent of the slope angle.

arctan 0.07 = 4.00 degrees

(4 degrees is the angle whose tangent is 0.07)
Answered by anna
how did u get the 4?
Answered by anna
nevermind my calculator was being stupid. thanks
Answered by drwls
I used the arctan key of my hand calculator. If you don't have one, you should use a table of trig functions
Answered by anna
sorry one more question. so...

a road climbs at an 8 degree angle with the horizontal. what is the grade of the road?

the answer would be 5?
Answered by drwls
The answer to your second question is the tangent of 8 degrees. That is 0.1405, for a 14.05% grade.

You don't find many roads that steep. Driveways, maybe.
Answered by fatass
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