goto_army.pas

var a,b,c,s,alpha,beta:real;

begin
    write('vvedite a=');
    readln(a);
    writeln('Axaxa, e6aHbII/I kopoTkoctBo/I');
    write('vvedite S=');
    readln(s);

    { povtorenye - mat' uchenya
    S=(a*b)/2
    a/b=tan(alpha)
    b/a=tan(beta)
    c=sqrt(a*a+b*b)
    alpha+beta=pi/2
    }

    b:=(2*s)/a;
    c:=sqrt(a*a+b*b);
    alpha:=arctan(a/b);
    beta:=arctan(b/a);
    { beta:=pi/2-alpha; //kak variant}

    writeln('a=',a:5:2,' b=',b:5:2,' c=',c:5:2);
    writeln('alpha=',alpha:6:3,' radian, beta=',beta:6:3,' radian');
end.