Answer is 5.4 units
Step by step.
I used Pythagorean theorem to find the diagonal (hypotenuse) of the triangle.
We know the height (y) is 5 and the other leg (x) is 2.
a^2 + b^2 = c^2 is the formula.
Substitute the two legs in for a and b.
5^2 + 2^2 = c^2
29 = c^2
Now take the square root of both sides
5.385 = c
Round to nearest tenth = 5.4 units