when two lines intersect, two pairs of angles are formed, They have the same measure. anyone know the blank ?! please help if you know thanks

I’m confused this is what i’m doing in class but the question is confusing

This law is sometimes called the grouping property. as you can see, regardless of how the numbers are grouped, the answer is still 13. the associative law of multiplication is similar to the same law for addition. it says that no matter how you group numbers you are multiplying together, you will get the same answer.