What is the area of a square with a side length of square root of 13

Which of the following is most likely the next step in the series? a3z, b6y, c9x, d12w, е15v, f18u

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)

Vertical angles must check all that apply