Questions | 5 |

Topics | Cubes, One Variable, Parallel Lines, Right Angle, Triangle Classification |

A cube is a rectangular solid box with a height (h), length (l), and width (w). The **volume** is h x l x w and the **surface area** is 2lw x 2wh + 2lh.

An equation is two expressions separated by an equal sign. The key to solving equations is to repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the equal sign and the answer on the other.

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°).

A right angle measures 90 degrees and is the intersection of two **perpendicular** lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.

An **isosceles** triangle has two sides of equal length. An **equilateral** triangle has three sides of equal length. In a **right** triangle, two sides meet at a right angle.