Which of the following figures is not a polygon?

Xto the second power plus 14x plus 48. what are the factors? we are doing factoring trinomials with a=1

Deshawn uses 3/4 of a box of rice to cook dinner the portion he uses weighs 12 ounces right and solve an equation to find the weight of the full box of rice

Solve each quadratic equation by factoring and using the zero product property. x^2 + 18x = 9x