1. The problem statement, all variables and given/known data I´ll show the problem with a picture: 2. Relevant equations Sum forces = 0 ; 3. The attempt at a solution Well I tried to solve the forces equations at the joint D, but I see three unkown quantities ED, BD and CD, and I have two equations, one for the X axis, and one for the Y axis so I cannot solve... or that´s what I thought until I saw that the book gives numerical answers to the problem. So, Anybody knows how to get three unkown quantities from two equations? I´m not able to do that, and until 5 minutes ago I thought it was impossible.