The diagram shos two horizontal parallel lines cut by a transversal line.
Therefore, angle 1 and angle 5 are corresponding angles, which means they are equal.
Also, angle 5 and angle 7 are vertically opposite angles, therefore angle 7 equals angle 5. Then angle 1 and angle 3 are vertically opposite, which means angle 3 equals angle 1.
The angles to angle 5 are angles 1, 3 and 7.
Please refer to the diagram above.
The angles congruent to the given angle (which is angle 43) are angle 2, angle 4 and angle 6.
Note that, angle 1 and angle 43 lie on a straight line. Angles on a straight line equals 180. Therefore, angle 1 plus angle 43 equals 180. This means angle 1 measures 137.
With this information we can now determine which angles are either opposite or corresponding to angle 43 and angle 137.
