How is the included angle for a taper of 0.550 TPF calculated?

The correct method to calculate the included angle for a taper of 0.550 TPF is by using a calculator. This is because taper calculations typically involve mathematical formulas that can require trigonometric functions to determine angles based on the taper per foot (TPF) measurement.

To find the included angle, you would take the taper value and apply the appropriate tangent function, using the relationship between the taper, the length, and the height difference to compute the angle in degrees. This precise calculation is best performed with a calculator to ensure accuracy, especially when working with decimal values.

Using a protractor, lookup table, or tape measure does not provide the necessary precision or the ability to perform the required trigonometric calculations effectively for this specific measurement of taper.