How can i calculate B if i dont know C?
A=50

B=50
Explanation
To find side B we can use the definition:
tan(angle)=opposite leg adjacent leg
In this case we have:
tan(B)=ba
After substituting b=45 degrees and A=50 we have:
tan(45degrees)=B50
B=50⋅tan(45degrees)
B=50⋅1
B=50

huh

im assuming the problem tells you if the triangle is 45-45-90 or 30-60-90.
i'll assume it's the latter because if it was a 45-45-90 triangle then B=50 since A=50.

so, we know tan(theta) = opposite/adjacent
theta= 60 degrees here and opposite=A=50.

then tan(60) = 50/B
tan(60) = sqrt(3)
so with algebra sqrt(3) = 50/B
B*sqrt(3) =50
B= 50/sqrt(3)

There is not enough data to conclude, there is an infinity of triangles with AB angle = 90deg and A side = 50... Please post the full problem