The triangles are congruent by using SAS.
We know these triangles are congruent by looking at the information given. The bottom sides have the same lengths, giving us one part of SAS.
We can also see an a right angle is given to us at the bottom, this automatically means the left angle is also a right angle. This is the angle of SAS.
Lastly, we know they share another side because they’re sharing the same side exactly.
