Answer: see attachment
Step-by-step explanation:
1) ∠5 & ∠ 4 form a linear pair (sum = 180°)
2) ∠2 & ∠9 are alternate interior angles (congruent)
3) ∠8, ∠9, & ∠ 10 are supplementary (sum = 180°)
4) ∠3, ∠4, & ∠9 form a triangle (Triangle Sum Theorem - sum = 180°)
5) ∠2, ∠7, & ∠8 form a triangle (Triangle Sum Theorem - sum = 180°)
6) ∠1 & ∠4 are consecutive (congruent)
7) ∠6 & ∠7 form a linear pair (sum = 180°)
