I’m klm, m=5.3 inches, k=21 and l=88. find the length of k

Ihonestly don’t understand this at all

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 area of a triangle with vertices at (-3 3) (-3,2) and (1,2)?