Two parallel lines are cut by a transversal. One angle formed measures 112°. What is the measure of the co-interior (same-side interior)…

Co-interior (same-side interior) angles formed by parallel lines and a transversal are supplementary, so they sum to $180^\circ$. The angle that is co-interior with the given $112^\circ$ angle is $180^\circ-112^\circ=68^\circ$, choice J. Choice F ($112^\circ$) is the measure of an angle that is congruent to the given one, such as a corresponding or alternate interior angle, rather than the co-interior one. Choice G ($78^\circ$) and choice H ($28^\circ$) do not relate to $112^\circ$ by any parallel-line rule. The two angles must add to a straight angle, so the answer has to be acute here.