camera 1
perimetrul (4+5)x2=18 m
suprafata = 18 x 2,6=46,8mp
camera 2
perimetrul (3+4)x2=14 m
suprafata = 14 x 2,6=36.4mp
total suprafata 46,8+36,4=83,2 mp
usi si ferestre 10%
83,2 mp x 10% = 8,32 mp
83,2-8,32 =74,88 mp 1 rulou =0,5x10=5mp
74,88 mp : 5 mp=14,976 buc se rotunjeste 15 roluri