You can put this solution on YOUR website! .
in rectangle abcd, diagonals bd and ac are drawn. prove angle dba is congruent to angle cab.
~~~~~~~~~~~~~~~~~~~~~
Consider two triangles, ABC and ABD.
They have common side AB.
They have congruent sides BC and AD (since these sides are the opposite sides of the rectangle.
Also, the triangles have the congruent angles ABC and BAD (they both are right angles).
Hence, the triangles ABC and ABD are congruent in accordance with SAS-test.
Therefore, the corresponding angles of these triangles, the angles DBA and CAB, are congruent.
It is what had to be proved.
