Aidez moi svvvvpp urgennnt exercice 1 et 2 merci

BR/BA=BS/BC=RS/AC=1/2
(RS)est parallele a(AC)(talles)
RS/AC=1/2⇔RS=AC/2
DT/DC=DU/DA=TU/AC=1/2
(TU)est parallele a(AC)(talles)
TU/AC=1/2⇔TU=AC/2
RSTU  est un paralelograme