rhombus

Because line AC splits angle ZAB into two equal angles, so ZAC=23, then ZAB=46. But because ZAB is a half of a rhombus, ABZ and AZB must be equal. Let's denote them: $x$. We have x+x+46=180, which gives 2x+46=180, which gives 2x=134, which gives $\boxed{x=ABZ=67^\circ}$

If ZAC = 23 that means CAB = 23 and we see there is a triangle and more importantly it is a Right triangle so that means 90+23 = 113 and we know that the angles of a triangle are equal to 180 meaning our equation is 180 - 113 = 67 degrees