Muslims achieve many spectacular advances, which was not one of them? a). they created the justinian's code. b). they corrected the star charts of the ancient greeks. c). they built public hospitals. d). they invented algebra.

answer: this problem has only trivial solutions, with all points on the same line. x=5 or x=7/5.

step-by-step explanation:

there are three triangles, and three unknowns: x, y=length of middle segment, and z=cos(angles marked with red arc).

we need

and law of cosines,

the three equations are

see attached image for solution.