how can I define the objective function of multivariate nonlinear optimization problem in MATLAB?

Question

clear

V = [31,0,-8;34,0,-14;35,8,0;38,0,-6;40,5,0;40,0,-10;45,5,0];    
F = [6,2,1;6,1,4;1,3,4;4,5,6;3,5,4;5,7,6];
l = [6.70820393249937,9.21954445729289,7.211102550927