你去看看初中数学!
需要哪些条件?比如三个边;两边一角什么的!就知道了啥!
type
TPoints=Array of TPoint
X,Youble
end;
function GetTrgArea(const x1,y1,x2,y2,x3,y3ouble)ouble
//三角形面积
var
a,b,c,CVouble;
begin
a:=Sqrt(Sqr(x1-x2)+Sqr(y1-y2));
b:=Sqrt(Sqr(x1-x3)+Sqr(y1-y3));
c:=Sqrt(Sqr(x2-x3)+Sqr(y2-y3));
if (a=0)or(b=0) then begin Result:=0
exit
end;
CV:=(sqr(a)+Sqr(b)-Sqr(c))/2/a/b;
Result:=a*b*Sqrt(1-Sqr(CV))/2;
end;