Program Example3;
uses Crt;
var
a,b,c,P,S :real;
begin
write('Nhap vao 3 canh : '); readln(a,b,c);
If (a<b+c) and (b<a+c) and (c<a+b) then
begin
P:=(a+b+c)/2;
S:=sqrt(p*(p-a)*(p-b)*(p-c));
writeln('3 canh ban vua nhap la 3 canh cua 1 tam giac.');
writeln('chu vi cua tam giac la : ',P*2:4:2,' cm');
writeln('dien tich cua tam giac la : ',S:4:2,' cm');
end
else
writeln('3 canh vua nhap khong la 3 canh cua tam giac');