What is the variable used to predict another variable called?

The base of a triangle is 8 1 3 meters and the height of the triangle is the fourth root of 16 meters meters. what is the area of the triangle?

The areas of two similar triangles are 72dm2 and 50dm2. the sum of their perimeters is 226dm. what is the perimeter of each of these triangles?

Ineed to know the ordered pairs for this equation i need the answer quick because it’s a timed test