--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/reference/quadrilaterals.ldr	Sun Jan 21 15:03:38 2018 +0200
@@ -0,0 +1,19 @@
+0 // square
+4 16 -20 0 10 -20 0 20 -10 0 20 -10 0 10
+0 // concave
+4 16 10 0 10 5 0 25 10 0 20 15 0 25
+0 // kite
+4 16 -15 0 -15 -20 0 0 -15 0 5 -10 0 0
+0 // bowtie
+4 16 5 0 -5 5 0 -15 15 0 -5 15 0 -15
+0 // trapezium
+4 16 25 0 10 30 0 20 35 0 20 40 0 10
+0 // skew
+4 16 25 0 -5 25 0 -15 35 0 -15 35 5 -5
+4 16 40 0 -5 40 0 -15 50 5 -15 50 0 -5
+0 // parallelogram
+4 16 25 0 25 30 0 35 40 0 35 35 0 25
+0 // rhombus
+4 16 -5 0 40 -15 0 35 -5 0 30 5 0 35
+0 // collinear
+4 16 20 0 40 30 0 45 30 0 50 30 0 55