Question 131868
Find a polynomial for the perimeter and for the area of the figure.
The problem says "square" but one side (the base) is given as 9+a and another side (the height) is given as a. It can't be a square, so presumably, it's a rectangle whose length (L) is 9a and whose width (W) is a.
The perimeter of a rectangle is:
P = 2L+2W Substitute the given values for L (9a) and for W (a):
P = 2(9a)+2(a) Simplify.
P= 18a+2a This is a polynomial for the perimeter.
The area of a rectangle is:
A = L*W  Substitute the given values for L (9a) and for W (a):
A = (9a)(a) Simplify. 
{{{A = 9a^2}}} This is not a polynomial but a monomial.