Questions | 5 |

Topics | Dimensions, Multiplying Binomials, Parallel Lines, Pythagorean Theorem, Triangle Geometry |

A circle is a figure in which each point around its perimeter is an equal distance from the center. The **radius** of a circle is the distance between the center and any point along its perimeter (AC, CB, CD). A **chord** is a line segment that connects any two points along its perimeter (AB, AD, BD). The **diameter** of a circle is the length of a chord that passes through the center of the circle (AB) and equals twice the circle's radius (2r).

To multiply binomials, use the FOIL method. FOIL stands for **F**irst, **O**utside, **I**nside, **L**ast and refers to the position of each term in the parentheses.

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°).

The Pythagorean theorem defines the relationship between the side lengths of a right triangle. The length of the **hypotenuse** squared (c^{2}) is equal to the sum of the two perpendicular sides squared (a^{2} + b^{2}): c^{2 }= a^{2} + b^{2} or, solved for c, \(c = \sqrt{a + b}\)

A triangle is a three-sided polygon. It has three interior angles that add up to 180° (a + b + c = 180°). An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite (d = b + c). The **perimeter** of a triangle is equal to the sum of the lengths of its three sides, the **height** of a triangle is equal to the length from the **base** to the opposite **vertex** (angle) and the **area** equals one-half triangle base x height: a = ½ base x height.