Imagine each horizontal line as 180 degrees. So if your angle measure on the top right is 81 the other side of that will be 99 degrees and then you can apply vertical angles. Since angle two is a vertical angle to the degree measure of 81 it is also 81. Which means angle three is equal to angle 1, which is 99 degrees. Now since the horizontal lines are parallel the same angle measure will apply to angles 4,5,6, and 7
Final answer angles 1,3,4,7 are 99 degrees
And angles 2,5,6 are 81 degrees