Geometry Basics Flashcards
Geometry Basics Flashcards
Cut along the dashed borders to create your study deck • Page 1 of 3
Building Blocks Angles Line Pairs
Building Block #1
P
Point
An exact location in space. It has no size, width, or length, and is shown as a dot.
Example: A city dot on a map or tip of a pin
Building Block #2
A B
Line
A straight path of points that goes on forever in both opposite directions.
Example: A straight horizon stretching across the sea
Building Block #3
A B
Line Segment
Part of a line with two clear endpoints. It has a definite, measurable length.
Example: A wooden pencil or one side of a ruler
Building Block #4
A B
Ray
Part of a line that starts at one endpoint and goes on forever in one direction.
Example: A beam of light shining from a flashlight
Geometry Basics Flashcards Page 2 of 3 • Angles & Line Pairs
Angle #5
< 90°
Acute Angle
An angle that measures greater than 0° and less than 90° (smaller than a square corner).
Example: A slice of pizza or slightly open scissors
Angle #6
90°
Right Angle
An angle that measures exactly 90°. It forms a perfect square corner.
Example: The corner of a book, door, or window
Angle #7
> 90°
Obtuse Angle
An angle that measures greater than 90° and less than 180° (wider than a square corner).
Example: An open laptop screen or reclining chair
Line Pair #8
Parallel Lines
Lines in the same flat plane that stay the exact same distance apart and never cross.
Example: Train tracks or opposite edges of a door
Geometry Basics Flashcards Page 3 of 3 • Line Pairs & Practice
Line Pair #9
Perpendicular Lines
Lines that cross or meet to form four 90° right angles (square corners).
Example: A plus sign (+) or a four-way street corner
Line Pair #10
Intersecting Lines
Lines that cross each other at exactly one shared point.
Example: The letter X or blades of open scissors
Your Turn Bonus #1
Draw the diagram:
Term:
Definition:
Your Turn Bonus #2
Draw the diagram:
Term:
Definition:
