To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce 36 as well and sum (Inside, Outside) to equal -12. For this problem, those two numbers are -6 and -6. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² - 12y + 36
y² + (-6 - 6)y + (-6 x -6)
(y - 6)(y - 6)

The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)² : a = π r².

The area of a rectangle is equal to its length x width:

a = l x w
a = a x b
a = 3 x 2
a = 6

A rectangle is a parallelogram containing four right angles. Opposite sides (a = c, b = d) are equal and the perimeter is the sum of the lengths of all sides (a + b + c + d) or, comonly, 2 x length x width. The area of a rectangle is length x width. A square is a rectangle with four equal length sides. The perimeter of a square is 4 x length of one side (4s) and the area is the length of one side squared (s²).

Perimeter is equal to the sum of the four sides:

p = a + b + c + d
p = 2 + 6 + 9 + 8
p = 25