Answer:
36 degrees
Explanation:
since, m<AOB is a right angle, we shall just create an equation:
M<AOB+M<BOC=90 degrees
Substitute: 6z-12+3z+30=90
Solve: 6z+3x=9z
-12+30=18
so, 9z+18=90 degrees
-18 -18
9z=72
z=8
So if z=8, then we should fit it so that it matches measure of AOB.
6z-12
6 times 8=48
48-12= 36