ex16.md

pair a,b,c;
numeric u;
u:=2cm;
a:=(0,0)*u;
b:=(1,0)*u;
c:=(0.5,0.8)*u;

draw a{up} .. c;
draw a{right} .. c;
draw a -- b;
draw c -- b;
drawdot a withpen pencircle scaled 2bp;