A Rhombus has four equal straight sides. We can assume that the rhombus in this problem is square-shaped with 90° angles.
m1 = 18x ; 90 = 18x ; 90/18 = x ; 5 = x
m2 = x + y ; 90 = 5 + y ; 90 - 5 = y ; 85 = y
m3 = 30z ; 90 = 30z ; 90/30 = z ; 3 = z
x = 5 ; y = 85 ; z = 3
x + y + z ⇒ 5 + 85 + 3 = 93
