Răspuns:
Explicație pas cu pas:
a) Aabc=AC·BD/2=16·12/2=8·12=96 cm²
Aabc=AE·BC/2 ⇒96=8·BC/2 ⇒⇒BC=96·2/8=12·2=24 cm
b) Aabc=AC·BD/2=20·12/2=10·12=120 cm²
Aabc=AE·BC/2 ⇒120=AE·15/2 ⇒AE=120·2/15=8·2=16 cm
c) Aabc=AE·BC/2 ⇒54=9·BC/2 ⇒BC=54·2/9=6·2=12 cm
Aabc=AC·BD/2 ⇒54=18·BD/2 ⇒BD=54·2/18=3·2=6 cm