Answer: 7.8
Step-by-step explanation: Identify the triangle as a 45-45-90 triangle.
Recognize that the sides of a 45-45-90 triangle are in a ratio of 1:1:√2.
Find the length of the hypotenuse of the triangle. In this case, the hypotenuse is 11 units.
Divide the length of the hypotenuse by √2 to find the length of the side opposite the 45-degree angle. In this case, the length of side x is 11/√2 = 7.77 units.
Round the length of side x to the nearest tenth. In this case, the length of side x is 7.8 units.