Answer:
this question isn't quite clear, is the diagram of the triangle necessary for me to answer this question ?
Explanation:
but by simple analysis,
since the "unknown" is b
option (a) which is 42 + b2 = 52 is the best equation.
because we are looking for the value of "b", therefore there should be letter "b" in equation we're going to use. hope you understand...
Hope this helps .