B is the correct answer.
HOPE IT HELPS U!!!!!
Answer:
Opposite Angles Theorem
Step-by-step explanation:
All opposite angles are congruent, meaning that two angles created by intersecting lines that oppose eachother are equal in size. The theorem goes by different names, so I don't know exactly what your teacher is asking for, but I hope I could help.
Just do 16-7 for your answer. Dan has 9 stamps