Răspuns :
desenezi trapezul si notezi AD baza mica si BC baza mare.
ducem AE perp pe BC.
in tr dr ACB,avem AB=12 si BC=24=>conf Teoremei 30-60-90 ca mas unghi C=30 grade.=>mas unghi B=60 grade
In tr de ABE,mas unghi B=60 grade=>mas unghi A=30 grade=>conf Teoremei 30-60-90 ca BE=AB/2=12/2=6cm
Duce si DF perp pe BC si avem ca si CF=6cm
Deci CB=BE+EF+CF=24=>EF=12cm=>AD=12cm
In tr dr ABE=>conform T Pitagora AE=6radical3
Aria trapez=(b+B)*h/2=36*6radical3/2=108radical3 cm ^2