# Теорема о квадрате
## Ссылка на видеоразбор
https://youtu.be/0Yp5sgddlko
## Код из сайта
    START_INTERACTIVE;;
    let coordinations =
    ["perpendicular", (** Lines (1,2) and (3,4) are perpendicular **)
    <<(1_x - 2_x) * (3_x - 4_x) + (1_y - 2_y) * (3_y - 4_y) = 0>>;
    "lengths_eq", (** Lines (1,2) and (3,4) have the same length **)
    <<(1_x - 2_x)^2 + (1_y - 2_y)^2 = (3_x - 4_x)^2 + (3_y - 4_y)^2>>;
    "is_midpoint", (** Point 1 is the midpoint of line (2,3) **)
    <<2 * 1_x = 2_x + 3_x /\ 2 * 1_y = 2_y + 3_y>>];;
    #Square theorem

    (grobner_decide ** originate)
    <<is_midpoint(m,a,c) /\ perpendicular(a,c,m,b)
    ==> lengths_eq(a,b,b,c)>>;;
    END_INTERACTIVE;