a) P=2l, A=49cm^2, l=49 deci l=7cm deci P=2x7=14cm
b) aplici regula de la a)
c) P=l+27
P=2 X l , deci 2l = l+ 27, deci 2l - l =27, deci l=27
A=l^2 DECI a = 27X27 = 729cm^2
d) P-l = 15, P=15 +l
P= 2l, deci 2l = 15 +l, deci l=15cm
P= 2xl = 2x15 = 30cm
A=l^2 = 15x15 = 225cm^2