{输入三角形三边的长,计算三角形的面积。}
program Project1;{$APPTYPE CONSOLE}uses
SysUtils;var
a, b, c, p, s: Real;
begin
read(a, b, c);
if ((a+b) > c) and (abs(a-b) < c) and ((a+c) > b) and (abs(a-c) < b) and ((c+b) > a) and (abs(c-b) < a) then
begin
p := (a+b+c)/2;
s := Sqrt(p*(p-a)*(p-b)*(p-c));
Writeln(s);
end
else
begin
Writeln('三边不能构成三角形');
end;
Readln;
Readln;
end.
program Project1;{$APPTYPE CONSOLE}uses
SysUtils;var
a, b, c, p, s: Real;
begin
read(a, b, c);
if ((a+b) > c) and (abs(a-b) < c) and ((a+c) > b) and (abs(a-c) < b) and ((c+b) > a) and (abs(c-b) < a) then
begin
p := (a+b+c)/2;
s := Sqrt(p*(p-a)*(p-b)*(p-c));
Writeln(s);
end
else
begin
Writeln('三边不能构成三角形');
end;
Readln;
Readln;
end.
program Project1;{$APPTYPE CONSOLE}var
a, b, c, p, s: Real;
begin
Readln(a, b, c); // Read -> Readln 吃掉确认的一个回车
if ((a + b) > c) and (Abs(a - b) < c) and ((a + c) > b) and
(Abs(a - c) < b) and ((c + b) > a) and (Abs(c - b) < a) then
begin
p := (a + b + c) / 2;
s := Sqrt(p * (p - a) * (p - b) * (p - c));
Writeln('三角形的面积是:', s);
end else Writeln('三边不能构成三角形');
Readln;
end.