This application is very good tool for kids to make a cone or frustum cone by using flat paper sheet. Also a very good tool for student, engineer and technical people to get all information for this cone to make it by using flat steel, aluminum or copper sheet. etcBy this app you can get: 1- Cone angle as the diameter and height are given. 2- Detailed drawing for the flat sheet needed to make this cone. 3- The area of this flat sheet.