Răspuns :
<NAD=<NAB+<BAD=90+60=150
ABCD=romb si ABMN=patrat, rezulta:
MN=NA=AD=DC=CB=BM=AB=7cm
P=6x7cm=42cm
ABCD=romb si ABMN=patrat, rezulta:
MN=NA=AD=DC=CB=BM=AB=7cm
P=6x7cm=42cm