Which is the equivalent of 0.00000000989 in proper scientific notation?

How do i solve using pythagorean theorem?

Atriangle has an area of 72 square inches. if the base of the triangle has a length of 18 inches, what is the height of the triangle? use the formula for the area of a triangle: area = (base)(height) type a numerical answer in the space provided. do not include the units or spaces in your answer.

What is the 17th term in the arithmetic sequence in which a6 is 101 and a9 is 83