The exterior angle is supplementary to the adjacent angle (they form a linear pair) and is the sum of the two angles in the triangle that are not adjacent to it. For example, in number 2, the exterior angle is 28+40=68 degrees. You can use the other method to check. 68 degrees is supposed to be in a linear pair with 112 degrees, which it is. So the answer to number 2 would be 68 degrees.
Try doing this for the rest of them
