Parallel lines are lines that share the same slope (steepness) and therefore never intersect. A transversal occurs when a set of parallel lines are crossed by another line. All of the angles formed by a transversal are called interior angles and angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°) and are called corresponding angles. Alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°) and 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°).

Perimeter is equal to the sum of the four sides:

p = a + b + c + d
p = 2 + 9 + 7 + 7
p = 25

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

a = l x w
a = a x b
a = 6 x 4
a = 24

According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:

c² = a² + b²
c² = 9² + 8²
c² = 81 + 64
c² = 145
c = \( \sqrt{145} \)

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