1) по заданному радиусу: Program n1;Uses CRT;Var r,s: real;beginClrScr;writeln('Vvedite radius');readln(r);s:=r*r*pi;Writeln('ploshad =',s:4:4);readlnend. 2) по заданным сторонам:Program n1;Uses CRT;Var a,b,s: real;beginClrScr;writeln('Vvedite storoni');readln(a,b);s:=a*b;Writeln('ploshad =',s:4:4);readlnend. 3) по заданной сторонеProgram n1;Uses CRT;Var a,s: real;beginClrScr;writeln('Vvedite storony');readln(a);s:=a*a;Writeln('ploshad =',s:4:4);readlnend. 3) по одной стороне и высоте к ней:Program n1;Uses CRT;Var a,b,s: real;beginClrScr;writeln('Vvedite storony i vysoty k nei');readln(a,b);s:=a*b;Writeln('ploshad =',s:4:4);readlnend.