Some examples:
point([1,2]) triangle([1,2],[3,4],[5,6]) triangle([1,2],[3,4],[5,6],red) triangle([1,2],[3,4],[5,6],green,filled) quad([1,1],[1,10],[10,10],[10,1]) a=[1,1] b=[20,1] c=[20,10] d=[10,15] e=[1,10] S=shape(a,b,c,d,e) translate(S,[10,10]) rotate(S,[20,20],90) reflect(S,[10,10],[20,20])you can have as many lines as you wish, points are specified by two number in square brackets [3,4].