Uses Crt;
Var
x1, x2, x3, y1, y2, y3, a, b, c: real;
Begin
ClrScr;
write('x1=');
Readln(x1);
write('y1=');
Readln(y1);
write('x2=');
Readln(x2);
write('y2=');
Readln(y2);
Write('x3=');
Readln(x3);
write('y3=');
Readln(y3);
a := sqrt(sqr(x1 - x2) + sqr(y1 - y2));
b := sqrt(sqr(x2 - x3) + sqr(y2 - y3));
c := sqrt(sqr(x1 - x3) + sqr(y1 - y3));
If (a = b) or (a = c) or (b = c) Then
Write('равнобедренный')
Else
Write('не равнобедренный');
Readln;
End.