Question

paralelogramul ABCD are perimetrul egal cu 24 cm.Determinati CD,știind ca AB=2BC

Answer 1

P=AB+BC+CD+AD, AB=CD, BC=AD AB=2BC ⇒ P=CD+CD/2+CD+CD/2=3CD ⇒

3CD=24, CD=24/3=8 cm

Answer 2

Salut!

P = 24 cm  

AB = 2BC

Știm că:

[AB] ≡ [CD], deci AB = CD

[BC] ≡ [AD], deci BC = AD

P = 2(AB + BC)

24 = 2(2BC + BC)

24 = 2 × 3BC

3BC = 12 cm

BC = 4 cm

AB = CD = 2BC

CD = 2BC

CD = 2×4

CD = 8 cm