35 lines
1.0 KiB
Racket
35 lines
1.0 KiB
Racket
#lang racket/base
|
|
|
|
(define (square x) (* x x))
|
|
|
|
(define (lengths_eq x1 y1 x2 y2 x3 y3 x4 y4)
|
|
(if (equal? (+ (square(- x1 x2)) (square(- y1 y2)))
|
|
(+ (square(- x3 x4)) (square(- y3 y4))))
|
|
(displayln "Lines (1,2) and (3,4) have the same length.")
|
|
(displayln "Lines (1,2) and (3,4) do not have the same length.")))
|
|
|
|
(define (perpendicular x1 y1 x2 y2 x3 y3 x4 y4)
|
|
(if (equal? (+ (* (- x1 x2) (- x3 x4)) (* (- y1 y2) (- y3 y4))) 0 )
|
|
#t #f
|
|
))
|
|
|
|
(define (is_midpoint x1 y1 x2 y2 x3 y3)
|
|
(if (and (equal? (* 2 x1) (+ x2 x3)) (equal? (* 2 y1) (+ y2 y3)))
|
|
(displayln "Point 1 is the midpoint of line (2,3).")
|
|
(displayln "Point 1 is not the midpoint of line (2,3).")
|
|
))
|
|
|
|
|
|
(define (grobner_decide_mid a_x a_y b_x b_y c_x c_y d_x d_y m_x m_y)
|
|
(if (and (is_midpoint m_x m_y a_x a_y c_x c_y)
|
|
(perpendicular a_x a_y c_x c_y m_x m_y b_x b_y))
|
|
(begin
|
|
(lengths_eq a_x a_y b_x b_y b_x b_y c_x c_y)
|
|
(displayln "This is a square.")
|
|
)
|
|
(displayln "This is not a square.")
|
|
))
|
|
|
|
|
|
|
|
(grobner_decide_mid 0 0 0 2 2 2 2 0 1 1) |