Which relation is a function

The perimeter of a stage is 116 feet. it is 17 feet wide. how long is it?

Aquadratic equation in standard from is written ax^2= bx+c, where a,b and c are real numbers and a is not zero?

72 the length of a side of a triangle is 36. a line parallel to that side divides the triangle into two parts of equal area. find the length of the segment determined by the points of intersection between the line and the other two sides of the triangle.