The answer should be 16/3
It is telling us that WP and XP are the same length. Therefor if we find WP then we find XP
HP^2 = WP^2 + HW^2
20/3^2 = x^2 + 4^2
400/9 = x^2 + 16
256/9 = x^2
16/3 = x
