1)
First 2 triangles can be proven similar but are not necessarily congruent since you can't from them using the side-angle-side or angle-side-angle or triple side rule.
2)
ONM = QNP since they are vertically opposite angles.
MON = NPQ given equal on the figure
ON=NP given
The two triangles are proven congruent using the angle-side-angle property.
3)
Last 2 pairs cannot be proven congruent as there is not enough info.
