Unit 1.2 Vocab

Front

Definition of parallel lines:

Back

Two lines with the same slope that never intersect.

Front

Definition of perpendicular lines:

Back

Two lines that intersect at a right angle.

Front

Straight angle: 180 degrees along a line.

Back

Not: 90 degrees (two angles), right angle (intersecting lines), or a line crossing two lines.

Front

Definition of a ray:

Back

A straight path starting at one point and extending infinitely in one direction.

Front

Vertical angles: angles opposite each other when lines cross, and they are congruent.

Back

Correct answer: angles opposite each other when lines cross, and they are congruent.

Front

Angle Addition Postulate: Sum of two adjacent angles equals the angle they form.

Back

Correct Answer: The sum of two adjacent angles is the measure of the angle they together form.

Front

Exterior Angle Theorem: The exterior angle equals the sum of non-adjacent angles.

Back

Correct: The exterior angle is equal to the sum of its non-adjacent angles.

Front

Acute angle: less than 90°

Back

An angle that is less than 90 degrees.

Front

Complementary angles:

Back

Two angles that sum to 90 degrees.

Front

Obtuse angle definition

Back

More than 90° but less than 180°.