AMC 10B 2018 Problem 22

Real numbers x and y are chosen independently and uniformly at random from the interval [0,1]. Which of the following numbers is closest to the probability that x, y, and 1 are the side lengths of an obtuse triangle?

Answer Choices
A. 0.21
B. 0.25
C. 0.29
D. 0.50
E. 0.79