Răspuns:
a) 1. AB≡DC, BC║AD, CD≡AB
2. ∠A≡B,D,C ∠B+∠C=∠A
3. AO≡OC, BO≡OD
b) 1. P= 2(4cm+ 3cm)=2×7cm=14cm(perimetrul palelogramului)
2. m(∠C)=m(∠A)=60°
3. m(∠B)=m(∠D)⇒60°+60°=120°⇒180°+180°=360°⇒360°-120°=240°⇒240°-180°=60°⇒∠B=120°
