program AreaOfRing;
var InnerRadius, OuterRadius: real;
procedure CalculateCircleArea(var Radius: real; var Area: real); begin Area := Pi * Radius * Radius; end;
var InnerCircleArea, OuterCircleArea, RingArea: real;
begin writeln('Введите внутренний радиус: '); readln(InnerRadius); writeln('Введите внешний радиус: '); readln(OuterRadius);
CalculateCircleArea(InnerRadius, InnerCircleArea); CalculateCircleArea(OuterRadius, OuterCircleArea);
RingArea := OuterCircleArea - InnerCircleArea;
writeln('Площадь кольца: ', RingArea:0:2);
readln; end.