How to convert a Double precision number into a string but showing only two decimal places in C++

fastcall TForm3::TForm3(TComponent* Owner)
	: TForm(Owner)
{
}
//---------------------------------------------------------------------------
void __fastcall TForm3::SpeedButton1Click(TObject *Sender)
{
double  m,dd,c,d,db,f,fc,asr,b,as_min;
 
 m=Umoment->Text.ToDouble();
 dd=Ddepth->Text.ToDouble();
 c=Co->Text.ToDouble();
 db=d_bar->Text.ToDouble();
 f=fy_reo->Text.ToDouble();
 fc=fc_concrete->Text.ToDouble();
 b=B_width->Text.ToDouble();
 
 
 
 d=dd-c-db*0.5;
 
 
 asr=(1-sqrt(1-3000000*m/(b*d*d*fc)))/(1.2*(f/(b*d*fc)));
 as_min=b*d*0.22*pow((dd/d),2)*0.6*(sqrt(fc))/f;
 
 
 d_depth->Text=String(d);
 Astr->Text=String(asr);
 
 Astm->Text=String(as_min);
 
 
return;