연습문제 2.49

a와 b만 푼다.. (나머지는 너무 많다. )

A. 그림틀의 테두리..

(define outline-segments
  (list
    (make-segment
      (make-vect 0.0 0.0)
      (make-vect 0.0 1.0))
    (make-segment
      (make-vect 0.0 0.0)
      (make-vect 1.0 0.0))
    (make-segment
      (make-vect 1.0 0.0)
      (make-vect 1.0 1.0))
    (make-segment
      (make-vect 0.0 1.0)
      (make-vect 1.0 1.0))))

(define outline-painter (segments->painter outline-segments))

B. X표시

<blockquote> (define x-segments<br />   (list<br /><pre>    (make-segment<br />      (make-vect 1.0 0.0)<br />      (make-vect 0.0 1.0))<br />    (make-segment<br />      (make-vect 0.0 0.0)<br />      (make-vect 1.0 1.0))))<br /><br />(define x-painter (segments->painter x-segments))