The measure of angle 1 and 2 should add up to 180°, because it forms a straight line. The same goes for the sum of angle 3 and 4.
Since we are given the measure of angle 2, we can find the measure of angle 1 by subtracting 143° from 180°.
180°-143° = 37°
We know that the intersecting lines form 2 sets of vertical angles, which are congruent. This means that the angles opposite from each other have the same measure. Therefore, both angle 2 & 4 have a measure of 143°, while angle 1 & 3 have a measure of 37°.
