Question

A diagonal of a rectangle is inclined to one side of the rectangle at 25º. The acute angle between the diagonals is (A) 55º (B) 50º (C) 40º (D) 25º

Answer 1

See diagram.

OAD = 25 deg. 
So ODA = 25 deg. from  symmetry of a rectangle.
So AOD  = 180 - 25 - 25 = 130 deg.

Hence, the acute angle  between diagonals :  180 - 130  = 50 deg.
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OR,

OAD = 25 deg.    So  BAO = 90 - 25 = 65 deg.
Since  ABO = BAO, it is also 65 deg.

Hence,  BOA = 180 - 65  - 65 = 50 deg.

Answer 2

Above picture contains the whole answer