The tangent of the angle is the ratio of rise to run, so the angle is ...
angle = arctan(rise/run) = arctan(4/25)
angle ≈ 9.1°
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<em>Comment on the angle</em>
Except in certain mountainous regions, the maximum grade of an interstate highway is limited to 6% (3.4°). The grade of this driveway is 16%, which would be considered very steep.
