Drawing a Graveyard Plan
Some Useful Geometry 



Two ways to plot a right angle:  


Choose distances x and y to avoid
Greater distances will produce a more 
This method is useful when there are
Any multiples of 3, 4 and 5 can be used, You could also use multiples of 5, 12 and 13. 



Checking that the grid is 'square':  


A true rectangle has equal diagonals A and B. 
A is shorter than B because the grid is 'off square'. 