Why dimension in triangles? The Cartesian coordinate system of X and Y values are easier to understand.
While they’re easy to understand, they’re hard to use to draw something as big as our sundial. Triangulation is much more accurate for drawing larger scale items.
When a carpenter sets out where to place the walls of a house, he will draw a right angle triangle that have sides of 3 x 4 x 5. This triangle can be any size as long as the proportions remain the same.
A layout triangle to obtain squareness can be
3ft x 4ft x 5ft
30in x 40in x 50in
3 meters x 4 meters x 5 meters
30ft x 40ft x 50ft
The sundial is set-out by using the same method.
All dimensions of the sundial are referenced from four set-out marks.
The triangle dimensions are given to you in an easy to follow format. These dimensions are in both inches and millimeters.
The marking of the hour points can be checked by using the Cartesian coordinate system (X and Y values)