The term that refers to ensuring surfaces are set at right angles is "Squaring."
When you square a surface, you are making sure that it is perfectly perpendicular or at a right angle to another surface. This process is essential in various fields such as carpentry, masonry, and metalworking to ensure accuracy and precision in the construction or fabrication of objects.
Squaring involves using tools like squares, levels, or measuring devices to check and adjust the alignment of surfaces to meet the desired right angle criteria. It is a fundamental principle in craftsmanship and engineering to achieve high-quality results.