21. Exemplar example problems I

1. If in the given figure, \(O\) is the point of intersection of two chords \(AB\) and \(CD\) such that \(OB = OD\), then triangles \(OAC\) and \(ODB\) are

 

 

2. \(D\) and \(E\) are respectively the points on the sides \(AB\) and \(AC\) of a triangle \(ABC\) such that \(AD = 2 \ cm\), \(BD = 3 \ cm\), \(BC = 7.5 \ cm\) and \(DE||BC\). Then, length of \(DE\) (in \(cm\)) is