BASIC TERMS
These lines maintain a constant distance and never intersect.
What are parallel lines?
These angles appear on opposite sides of a transversal and between two lines.
What are alternate interior angles?
If one angle formed by two intersecting lines is 90°, all angles measure this.
What is 90 degrees?
This property states that if line A ∥ line B and line B ∥ line C, then line A ∥ line C.
What is the transitive property?
These parallel lines on the road tell drivers where lanes are.
What are lane markers?
A line that intersects two or more other lines is called this.
What is a transversal?
When two parallel lines are cut by a transversal, these angles always sum to 180°.
What are consecutive interior angles?
200: If one corresponding angle measures 120°, all corresponding angles measure this.
What is 120 degrees?
To prove lines are parallel, you must prove these types of angles are congruent.
What are corresponding or alternate interior angles?
Railroad tracks are designed to be these types of lines.
What are parallel lines?
These lines intersect to form exactly four 90-degree angles.
What are perpendicular lines?
These angles are on the same side of the transversal and on the same positions relative to the parallel lines.
What are corresponding angles?
If an alternate interior angle is 45°, its pair measures this.
What is 45 degrees?
This tool along with a straightedge is used to construct parallel lines.
What is a compass?
The edges of a properly built door frame should form these types of angles.
What are right angles/90-degree angles?
Lines in different planes that never intersect are called this.
What are skew lines?
If two parallel lines are cut by a transversal, these angles are found outside the parallel lines on opposite sides.
What are alternate exterior angles?
When two parallel lines are cut by a transversal, consecutive interior angles sum to this.
What is 180 degrees?
This postulate states that through a point not on a line, exactly one parallel line can be drawn.
What is the Parallel Line Postulate?
This letter of the alphabet demonstrates both parallel and perpendicular lines.
What is the letter H?
Through any given point not on a line, exactly this many parallel lines can be drawn to the original line.
What is one?
When these types of angles are congruent, it proves that two lines cut by a transversal are parallel.
What are alternate interior or corresponding angles?
If one angle in a pair of complementary angles is 35°, the other angle measures this.
What is 55 degrees?
When proving angles congruent, this property states that if A = B and B = C, then A = C.
What is the transitive property of congruence?
These support beams in construction must be perpendicular to the ground for maximum stability.
What are vertical columns/pillars?