Răspuns:
11. a) P=4*l = 4*7,2= 28.8 cm
12. a) P=2L +2l= 2*5.4+2*4.6= 10.8+ 9.2 = 20 cm
13. a) A= l*l= 14*14= 196 [tex]cm^{2}[/tex]
14. a) A= L*l = 9.5*12= 114