(16)Pdr=2L+2l=240
l=3/5×L
2×3×L/5+2L=240.…aducem la acelasi numitor=>
=>6L/5+10L/5=1200/5
=>16L/5=1200/5=>
=>16L=1200=>
=>L=75
V: 2×3×75/5+2×75=
=6×15+150=
=90+150=
=240
(17) L=l-165}=>l=165+L
L=l/4=>L=165+L/4=>
=>4L=156+L=>3L=156=>
=>L=156/3=52
L=l/4=>l=4L=>l=4×52=>
=>l=208
P=2l+2L
P=2×208+2×52=>
=>P=416+104=520m