JK = 5x, KL = 2x, and JL = 49

Use pythagorean’s theorem and find the missing side lengths of the two smaller triangles and add them together
13^2 - 12^2 = 5
15^2 - 12^2 = 9
5+9 = 14
14 is the length of each side of the square
14^2 + 14^2 = 19.8
19.8 is the diagonal length of the inside if the square

Hi there the answer is list some answer choices i would say 10 if the number line is from 0 to 10 but just pick the last number mark me brainliest and hope this : )