What you are going to need to do ( I believe from my prior knowledge), you need to find the opposite of the 60° first. Your calculator needs to be in degree mode. 1st equation;
(60)tan(x/4sq14)
Once you find this answer, apply it to the opposite of the 60° angle on the far right.
Then you are going to do the solution of the equation I just stated above, times 4sq14 using the Pythagorean theorem theory shown down below.
a^2 + b^2 = c^2
first answer^2 + 4sq14^2 = C^2
C^2 will then provide the short legs of the larger triangle (they are congruent lengths in a 45-45-90 triangle)
Multiply the value of c times c without squaring either of them, like so, this will lead to the answer of X
C times C = “x”
Hope this helps!