The coordinate grid is composed of a horizontal x-axis and a vertical y-axis. The center of the grid, where the x-axis and y-axis meet, is called the origin.

For parallel lines with a transversal, the following relationships apply:

• angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°)
• alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°)
• all acute angles (a° = c° = w° = z°) and all obtuse angles (b° = d° = x° = y°) equal each other
• same-side interior angles are supplementary and add up to 180° (e.g. a° + d° = 180°, d° + c° = 180°)

Applying these relationships starting with a° = 13, the value of z° is 13.

A monomial contains one term, a binomial contains two terms, and a polynomial contains more than two terms.

The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:

a² - 2a - 3 = 0
(a + 1)(a - 3) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (a + 1) or (a - 3) must equal zero:

If (a + 1) = 0, a must equal -1
If (a - 3) = 0, a must equal 3

So the solution is that a = -1 or 3

The perimeter of a triangle is the sum of the lengths of its sides:

p = x + y + z
p = 5cm + 6cm + 6cm = 17cm