Projection calculators are employed by architects to determine angles and the positions of buildings. They also play a significant role in the visualization of architectural structures. A basic projection calculator is a square, rectangular, or cylindrical lens with fixed, nonzero, rotating coordinate scheme, as well as a set fixed, nonzero, orthogonal coordonnée systems. These coordinate systems can be used to calculate x, y, and z values directly from the source point. Projection calculators are useful for applications that require precise measurements of angles, distances and surfaces like facades and roofs. There are two types of projection calculators: those that use circular coordinates and those that make use of cylindrical coordinates.