You got general direction of the wind that files that you wish to deploy should be placed in webapps folder, unfortunately it is not full truth.
You need to provide your "ch" folder with minimal Tomcat deployment directory structure.
Create new project folder in directory webapps (you already did this with creating new folder named ch)
Place context.jsp in "ch" folder (you already did)
In project folder create another folder called WEB-INF where you will save web.xml
<?xml version="1.0" encoding="ISO-8859-1"?>
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"