How to Find the Grade of a Right Triangle

If you take a high school or college geometry course, you may be required to find the grade of a right triangle. Working with grades also is a task used in engineering and design. For instance, landscape specialists must figure the grade of a yard in order to determine its drainage. Grade is a term used to denote the slope of a line. The formula for slope is rise over run. You can apply this formula to a right triangle in order to determine its grade.

Things You'll Need

• Right triangle
• Ruler or tape measure
• Calculator (optional)

Instructions

1. Measure the length of the vertical leg of the triangle (the rise). If you were calculating the slope of a hill, the rise would be the height of the hill, say 3 feet.

2. Measure the length of the horizontal leg (the run) of the triangle. If the bottom of your hill extends 10 feet out from its highest point, the run is 10 feet.

3. Divide your measurement from Step 1 ("rise") by your measurement from Step 2 ("run"). For instance, if the vertical leg is 3 feet and the horizontal leg is 10 feet, divide 10 into 3 to get 0.3. Therefore, your slope or grade would be 0.3.

References

• Auburn University: Slope and More
• Southeastern Louisiana University Computer Science Portal: Slope formula