Answer:
3√2
Explanation:
The large triangle is made up of two smaller 45-45-90 triangles. The legs of each of these are equal and measure 3 each.
The hypotenuse, x, can be found as follows, using the Pythagorean Theorem:
x² = 3² + 3², or x² = 2·9.
Taking the square root of both sides, we get x = 3√2. This corresponds to the fourth possible answer choice.