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).

To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

(2a)(3ab) + (3a²)(4b)
(2 x 3)(a x a x b) + (3 x 4)(a² x b)
(6)(a¹⁺¹ x b) + (12)(a²b)
6a²b + 12a²b
18a²b

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 w° = 37, the value of d° is 143.

To solve this equation, isolate the variable for which you are solving (a) on one side of the equation and put everything else on the other side.

3a + 3z = a - 4z + 2
3a = a - 4z + 2 - 3z
3a - a = -4z + 2 - 3z
2a = -7z + 2
a = \( \frac{-7z + 2}{2} \)
a = \( \frac{-7z}{2} \) + \( \frac{2}{2} \)
a = -3\(\frac{1}{2}\)z + 1

A rhombus is a parallelogram with four equal-length sides. A square is a rectangle with four equal-length sides.