answer
z = 100
opposite angles
when inscribed in a circle, the opposite angles of a quadrilateral add up to 180
so z + 80 = 180 and y + 120 = 180
solve for z
z + 80 = 180
z = 180 - 80
z = 100
There’s are ratio which would be 8/10. 12/x should equally 8/10. So it would be 14 tiles long.
The answer would be 11x-12