18 terms

Lines

A straight path of points that has no endpoints.

Rays

A part of a line that has one endpoint and continues in one direction infinitely.

Line segments

A part of a line with two endpoints.

Angle

A figure formed by two rays with a common endpoint, called the vertex. The rays are called sides.

Acute angles

An angle with a measure less than 90°.

Right angle

An angle with a measure of 90°.

Obtuse angles

An angle with a measure greater than 90° and less than 180°.

Straight angles

An angle with a measure of 180°.

Parallel lines

Never cross because they are always the same distance apart

Conplementary angles

Two angles whose measures have a sum of 90°.

Supplementary angles

Two angles whose measures have a sum of 180°.

Corresponding angles

Angles that are in the same position from one line to the other. (Congruent)

Vertical angles

A pair of opposite congruent angles formed by intersecting lines. (Congruent)

Adjacent Angles

Angles that have:

~a common side

~a common vertex

~No common interior points (Supplementary)

~a common side

~a common vertex

~No common interior points (Supplementary)

Alternate Interior Angles

Pairs of non-adjacent angles both interior and on opposite sides of the transversal. (Congruent)

Alternate Exterior Angles

Pairs of non-adjacent angles both exterior and on opposite sides of the transversal. (Congruent)

Perpendicular Lines

Form right angles when they intersect each other

Transversal Line

Intersects two or more lines at different points