According to the Alternate Exterior Angles Theorem if a pair of Parallel lines are intersected by a transversal(t) then the alternate exterior angle are congurent.-Alternate Exterior Angles theorem and Linear Pair theorem
Explanation:
Alternate exterior angles are said to be those angles that are outside the "block" which is formed by the parallel lines and are placed on the opposite sides of the transversal(t)
From the question we can say that both ∠2 and ∠7 are outside the parallel lines and ∠2 is on the right side of the transversal (t) and ∠7 is on the left side of the transversal. This makes ∠2 and ∠7 alternate exterior angles.
A linear pair is referred to as a pair of angles that are formed from a straight line. When ∠7 and ∠8 combined together they form a straight line this makes them a linear pair.
According to the Alternate Exterior Angles Theorem if a pair of Parallel lines are intersected by a transversal(t) then the alternate exterior angle are congurent. Hence both Alternate Exterior Angles theorem and Linear Pair theorem is applicable