Answer:
4th answer option
Explanation:
both side angles are 45°, that makes the triangle an isoceles triangle (both legs are equally long).
therefore, v = 7.
Pythagoras gives us
c² = a² + b²
with c being the Hypotenuse (the side opposite of the 90° angle), a and b being the legs.
in our case
u² = 7² + 7² = 49 × 2
u = sqrt(49 × 2) = 7 × sqrt(2)