1)81° due to the fact that 99° and (1) are supplementary angles 2)99° due to the fact that (5) and (2) are adjacent angles that sum up to equal 180° 3)81° due to the fact that it is the corresponding angle to (5) 4)99° due to the fact that (4) and (2) are alternate interior angles which equal the same 5)81° due to the fact that (5) and (6) are adjacent angles which means they are supplementary angles that add to equal 180° 6)99° due to the fact that (6) and (2) are corresponding angles which equal the same value 7)81° due to the fact that (7) and (3) are corresponding angles with equal the same degree
