2+2

2 + 2 = 4

Regarding the image with trapezoid ABCD, you need to find pairs of similar triangles:

1. In trapezoid ABCD with diagonals intersecting at O, triangles ABO and CDO can be similar if angles AOB and COD are equal, and AB/AD = BC/CD.
2. Similarly, triangles AOD and COB can be similar under the same angle and proportionality conditions.

To prove their similarity, you can use the Angle-Angle (AA) criterion, where two pairs of angles must be equal for the triangles to be similar.