Angles are congruent if they have same angle measure.
Let us consider the given pairs one by one.
A. ∠MKR and ∠OAR
From the figure it is clear that the angle bisector of the right angled vertices form the angles MKR and OAR.
Hence they are congruent with value 45°
B. ∠ONT and ∠MTN
From the figure, MTN is right angled, where as ONT is formed by bisecting the right angle.
So, the angles are not congruent with ∠MTN = 90° and ∠ONT = 45°
C. ∠IRS and ∠MRO
From the figure, MRO is right angled, where as IRS is formed by bisecting the right angle.
So, the angles are not congruent with ∠MRO = 90° and ∠IRS = 45°
D. ∠URC and ∠TRO
From the figure it is clear that the angle bisector of the right angled vertices form the angles URC and TRO.
Hence they are congruent with value 45°
∴ The pair of congruent are angles are
A. ∠MKR and ∠OAR and D. ∠URC and ∠TRO
