What is the area of a circle with diameter = 4ft, using 3.14 for ? thx :)

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.

Icould really use some with this question.

Will give a: 122 b: 90 c: 48 d: 180