Răspuns:
Explicație pas cu pas:
ΔABD asemenea cu ΔABC (UUU) => unghi C=unghi BAD,
ctgC=ctgBAD
ctg BAD=AD/BD =>AD/20,25=4/3 =AD=4*20,25/3=27cm
Aplicam Pitagora in ΔABD si aflam AB
AB2=BD2+AD2=410,625+729=1139,725
AB=33,76cm
ctgC=AC/AB=4/3
AC=4AB/3=81/3=27cm
Aplicam Pitagora in ΔABC:
BC2=AB2+AC2=1139,725+729=1868,725
BC=43,23cm
Acum ai toate laturile, le aduni si afli perimetrul.
Spor
