The circumference of a circle is 21 pi inches. what is the area, in square inches, of the circle? express your answer in terms of pi

Need on this one asap im almost done with this subject

Which is a graph of a proportional relationship?

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.