1. The problem asks to identify the relationship between angles 1 and 7 formed by two parallel lines $a$ and $b$ cut by a transversal $h$. 2. Important definitions: - Vertical angles are opposite angles formed by two intersecting lines and are always equal. - Corresponding angles are on the same side of the transversal and in corresponding positions relative to the parallel lines. - Alternate interior angles lie between the parallel lines but on opposite sides of the transversal. - Alternate exterior angles lie outside the parallel lines and on opposite sides of the transversal. 3. Given angles 1 and 7 are both on the top-left of their respective intersections but at different parallel lines. 4. Since they are on the same side of the transversal and in corresponding positions relative to lines $a$ and $b$, angles 1 and 7 are corresponding angles. 5. Therefore, the best description of the relationship between angles 1 and 7 is: **corresponding angles**.