By looking at the diagram, we see that angle C is 45 degrees, angle A is 90 degrees, and angle B is unknown
Given that the sum of all the triangle's angle is 180 degrees, angle B is also 45 degrees
This means that we have a 45-45-90 triangle, which has some special properties as shown in the diagram I uploaded.
Thus <u>BC in the simplest term is </u>
Hope that helps!