When using 45° elbows to calculate an offset, what is true about the rise and run?

When using 45° elbows to calculate an offset in plumbing, the relationship between rise and run is based on the geometry of the triangle formed by the offset. With 45° elbows, each elbow effectively creates an angle that allows the rise and the run to be proportional.

In this scenario, both the rise and the run are equal in length. This equality stems from the properties of a right triangle where the angles are 45°, 45°, and 90°. In this case, the two legs of the triangle (which represent the rise and the run) are the same length, confirming that when you utilize two 45° elbows in a plumbing application, they create a vertical rise that matches the horizontal run.

Understanding this relationship is crucial for accurate plumbing layout and installation, ensuring that piping fits properly in the intended space and maintains effective drainage and flow characteristics.