a) P=1.8×1.8=3.24m²
b) Ob=2.5×2+6.8×2=5+13.6=18.6m P=2.5×6.8=17m²
c) Ob=3.4×2+8.5×2=6.8+17=23.8m P=3.4×8.5=28.9m²
d) Ob=14.25×2+11.2×2=28.5+22.4=50.9m P= 14.25×11.2=159.6m²
