The Angle of a Ramp
Part of the Right-Triangle Trigonometry section of Coddy's Trigonometry journey. Lesson 26 of 50.
US accessibility rules limit a wheelchair ramp to a rise of 1 for every 12 along the ground. Rise and run are the two legs, so the angle comes from arctan, and one decimal place is enough to compare it with the limit.
A ramp that rises 0.6 m over 9 m of run has tan(theta) = 0.6/9. arctan gives about 3.814°, and to one decimal place that is 3.8°. The second decimal tells you whether the first goes up: here it is 1, so it stays.
Challenge
A ramp rises 0.75 m over a run of 10 m. Find the angle θ it makes with the ground, in degrees, rounded to one decimal place. Then press Check.
Try it yourself
Use the figure to find theta
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Right-Triangle Trigonometry
1Sides of a Right Triangle
How Tall Is the Tree?The HypotenuseThe Opposite SideThe Adjacent SideWhen the Angle MovesRecap: Naming the Sides2The Three Ratios
The Sine RatioThe Cosine RatioThe Tangent RatioChoosing the RatioRecap: The Three Ratios5Finding an Angle
Inverse SineInverse CosineInverse TangentThe Angle of a RampBoth Acute AnglesRecap: Finding an Angle