1)
NO = OP
OM = OM } => ΔMNO = ΔMPO =>
∡MNO = ∡PMO
MN = MP si RM = RM } => ΔMNR = ΔMPR
2)
a)
∡OAD = ∡OCD
OA = OC } => (U.L.U.) => ΔBOC = ΔDOA => OB = OC
∡O = ∡O
b)
OB = OA + AB
OD = OC + CD } => AB = CD
OB = OC si AO = CO
c)
∡AEB = ∡DEC
AB = CD } => (U.L.U.) => ΔABE = ΔCDE => AE = CE
∡EDC = ∡EBA
OE = OE
∡OAE = ∡OCE } => (L.U.L.) => ΔOAE = ΔOCE => ∡AOE = ∡COE
d)
ΔOAE = ΔOCE => ∡AEO = ∡CEO
AE = CE