Complementary angles are angles that sums up to 90 degrees
Since a ray intersects two other rays forming a right angle, hence the sum of the two angles is 90degrees and this shows that the angles are complementary.
Given the two angles to be x and (x-20). Taking their sum and equating it to 90 degrees, we will have;
16 divided by 8 is 2, which means that each track practice, she ran 2 miles. So then I did 20 divided by 2 is 10, which means that she ran 20 miles in 10 track practices.
