Lines AB and CD are parallel. If 1 measures (3x + 12)°, and 4 measures 156°, what is the value of x?
Since lines AB and CD are parallel, angles 1 and 4 are corresponding angles and therefore congruent. This means that (3x + 12)° = 156°.
Solving for x:
3x + 12 = 156
3x = 144
x = 48
Therefore, the value of x is 48.