Answer:
z = 56
Step-by-step explanation:
z + 68 + z = 180
2z + 68 = 180
2z = 180 - 68
2z = 112
2z/2 = 112/2
since KJ and HI are parallel
z+68+z=180(cointerior angles sum up to 180)
2z+68=180
2z=180-68
2z=112
z=112/2
z=56
