a) 30 radical 3 30 ABCD = A = 900
b)
MNAC si MQBD (m(∢NMQ) = m(∢COD) si O = punct de intersectie la diagonalele dreptunghiului ABCD2PAC =BD=60=OD=OC=CD=OCD e echilateral deci m=60 grade
c)
BM MNMN AC BMN BAC MNBA AC --> 1p40 m AM MQMQ BD AMQ ABD MQAB BD deci 2pMNPQ e paralelogram deci = 120 m