Lời giải :
program hotrotinhoc ;
var a,b,c : integer ;
begin
write('nhap gia tri a'); readln(a);
write('nhap gia tri b'); readln(b);
write('nhap gia tri c'); readln(c);
If (a+b>c) or (a+c>b) or (b+c>a) then write('Chung la ba canh cua tam giac') else write('Chung khong phai la ba canh cua tam giac');
readln
end.