examples/ex-8.rkt
#lang racket
(require (planet wcy/mpost-wrapper))
(provide main)
(define (A-B-C)
  (values (point 0 0)
          (point '1cm 0)
          (point 0 '1cm)))
(define (main)
  (call-with-values A-B-C
    (lambda (A B C)
      (draw (op-- A  B  C 'cycle))
      (draw (op-- (mediation 0.5 B C) A))
      (draw (op-- (mediation 0.5 A C) B))
      (draw (op-- (mediation 0.5 B A) C))
      (draw (op* 1/3  (op+ A B C))
            #:withpen (scale '4bp 'pencircle))
      )))