Răspuns:
Explicație pas cu pas:
LM =AB+CD/2
LM =24+12/2=36/2 =18 cm
CD // AB =>
DE/AE=CD/AB=CE/BE
DE/DE+12 =12/24
24DE =12(DE+12)
24DE =12DE+144
24DE-12DE =144
12DE=144
DE =12 cm
AE=DE+AD =12+12 =24 cm
AE=BE=AB =24 cm
=>Δ AEB echilateral
=> ∡ ABE =B=E =60°
A =l²√3 /4
A =24²√3/4
A =576√3/4 =144√3 cm²