I have one very important question. I am a student doing BTEC level 3 in aeronautical engineering. I am actually designing an aerofoil of an aircraft wing by using SOLID WORKS2015. All the information is correct about the coordinates and there was a little gap between the two points at the trailing edge so I drew a line there to fill that gap but still I was not able to extrude it. I am really confused about this extruding problem as I have not used SOLIDWORKS ever before. I hope that you will answer my question as soon as possible. I will be waiting to your reply.