Step-by-step explanation:
GIVEN: O is the mid point of AC & BD.
Therefore, AO = CO & BO = DO
[tex] \therefore \: AO \: \cong \: CO.. (given) \\ \\ \: \: \: \: \angle \: AOB \: \cong \:\angle \:COD\\..(vertically\:opposite\:angles) \: \\ \\
\& \: \: \: BO \: \cong \: DO.. (given) \\ \\ \therefore \triangle \: AOB \: \cong \: \triangle \:COD \\ ..(by \: SAS \: test \: of \: congruence ) \\ \\ \therefore AB = CD.. \\ (Corresponding \: sides \: of \: congruent \: triangles)[/tex]
