Question

Can you please help meeee ??

Answer 1

What you can do for this case is to use the following trigonometric definition.
 sine (x) = a / h
 Where,
 a: side of the triangle.
 h: hypotenuse.
 Clearing to:
 a = sin (x) * h
 Substituting:
 a = sine (45) * (4)
 a = (root (2) / 2) * (4)
 a = 2raiz (2) cm
 Answer:
 2raiz (2) cm (option 2)

Answer 2

Your answer is the first option.