Is the number 4.277777777... rational or irrational

Two lines that do not intersect are skew. always sometimes or never

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.

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.