Answer:
B. 11√2
Explanation:
x is the length of the hypotenuse of an isosceles right triangle with leg length 11. Its measure is x = 11√2.
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Consider a right triangle with legs (a and b) of length 1. Then the Pythagorean theorem tells you the hypotenuse (c) has length ...
c = √(a²+b²) = √(1²+1²) = √2
This same ratio of leg lengths to hypotenuse length (1 : 1 : √2) applies to all isosceles right triangles. So, the length of the hypotenuse is always √2 times the length of a leg in such a triangle.