progam ban_tu_chon;

uses crt;

var a,b,c :real;

BEGIN

clrscr;

write('nhap canh a thu nhat'); Read(a);

write('nhap canh b thu hai:'); Readln(b);

write('nhap canh c thu ba'); Readln(c);

if (a>=b+c) or (b>=c+a) or (c>=a+b) then write('ba canh tren khong phai cua mot tam giac')

else

if (a=b) or (b=c) or (c=a) then write('tam giac tren la tam giac can');

else

if a=b=c then write('tam giac tren la tam giac deu')

else

if (a*a=b*b+c*c) or (b*b=c*c+a*a) or (c*c=a*a+b*b) then write('tam giac tren la tam giac vuong');

readln;

END.