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#lang racket
(require "../../shared/chapter1.rkt")
(define (make-segment p1 p2)
(cons p1 p2))
(define (start-segment s)
(car s))
(define (end-segment s)
(cdr s))
(define (make-point x y)
(cons x y))
(define (x-point p)
(car p))
(define (y-point p)
(cdr p))
(define (print-point p)
(newline)
(display "(")
(display (x-point p))
(display ",")
(display (y-point p))
(display ")"))
(print-point (make-point 36 7))
(define (midpoint-segment s)
(make-point
(average (x-point (start-segment s)) (x-point (end-segment s)))
(average (y-point (start-segment s)) (y-point (end-segment s)))))
(define start (make-point 36 7))
(define end (make-point 36 9))
(define line (make-segment start end))
(define mid (midpoint-segment line))
(print-point mid)
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