Congruent angles have the same measurement.
Let’s evaluate the provided pairs one by one.
A. ∠MKR and ∠OAR
In the diagram, it’s visible that the angle bisector of the right-angled vertices creates angles MKR and OAR.
Thus, they are congruent measuring 45°
B. ∠ONT and ∠MTN
From the diagram, MTN forms a right angle, while ONT is created by bisecting this right angle.
Hence, these angles are not congruent with ∠MTN at 90° and ∠ONT at 45°
C. ∠IRS and ∠MRO
In the diagram, MRO is a right-angle, while IRS results from the bisection of the right angle.
Accordingly, these angles are not congruent with ∠MRO equal to 90° and ∠IRS at 45°
D. ∠URC and ∠TRO
In the diagram, it’s shown that the angle bisector of the right-angled vertices forms angles URC and TRO.
Thus, they are congruent, both measuring 45°
Therefore, the pairs of congruent angles are
A. ∠MKR and ∠OAR and D. ∠URC and ∠TRO