Answer is:
∠2 and ∠3
Explanation:
Exterior angle of a triangle is formed by extending one of the sides of the triangle.
Each exterior angle in a triangle has two remote interior angles. These two angles are the two angles in the triangle that are not adjacent to this exterior angle
In the given triangle:
Angles of the triangle are: angles 2,3 and 4
The exterior angle under study is: angle 1
The adjacent angle to angle 1 from the angles of the triangle is angle 4
Therefore, the remote exterior angles to angle 1 will be the other two angles in the triangle which are angles 2 and 3
Hope this helps :)