main.jsp代码

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ include file="circle.jsp" %>

<%@ include file="ladder.jsp" %> 

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
  </head>
  
  <body>
  
  </body>
</html>

circle.jsp代码

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
  </head>
  
  <body>
    <div>
        <form action="main.jsp">
                请输入半径：<input type="text"  name="R" > <br>
         <input type="submit" value="计算"> <br>
        </form>
    </div>
    <%
        String R=request.getParameter("R");
        if(R!=null){
            double PI=3.14;
            double r=Double.parseDouble(R);
            double area=r*r*3.14;
            out.print("圆的面积为"+area);
            request.setAttribute("r", r);
            request.setAttribute("area", area);
        }
        
    %>
  </body>
</html>

ladder.jsp代码

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
  </head>
  
  <body>
    <div>
        <form action="main.jsp">
       请输入梯形上底: <input type="text" name="a"> <br>
       请输入梯形下底: <input type="text" name="b" > <br>
       请输入梯形的高: <input type="text" name="h"> <br>
         <input type="submit" value="计算"> <br><br>
         </form>
     </div>
          <%
        String a=request.getParameter("a");
        String b=request.getParameter("b");
        String h=request.getParameter("h");
        if(a!=null&&b!=null&&h!=null){
            double A=Double.parseDouble(a);
            double B=Double.parseDouble(b);
            double H=Double.parseDouble(h);
            double M=(A+B)*H/2;
            out.println("梯形面积"+M);
            request.setAttribute("A", a);
            request.setAttribute("B", b);
            request.setAttribute("H", h);
            request.setAttribute("M", M);
        }
    %>
  </body>
</html>

运行图片

1）.圆形

 

 

2）.梯形