Busy. Please wait.
Log in with Clever

show password
Forgot Password?

Don't have an account?  Sign up 
Sign up using Clever

Username is available taken
show password

Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
Your email address is only used to allow you to reset your password. See our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Didn't know it?
click below
Knew it?
click below
Don't Know
Remaining cards (0)
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Module Geometry

All important words in geometry

Point A point is a location with no size or shape
Line A line is made up of points with no thickness or width
Line Segment A measurable part of a line consisting of 2 endpoints
Ray Part of a line that extends indefinitely in one direction
Plane A plane is a flat surface made up of points and expands indefinitely in all directions
Collinear Points that lie on the same line -- non-collinear; points that don't lie on the same lines
Coplanar Points that lie on the same plane -- non-coplanar; points that don't lie on the same plane
Congruent Segments If 2 segments have the same length then they are congruent
Segment Addition Postulate If A, B, and C are collinear points and B is between A and C, then Ab + BC = AC
Distance Formula The formula used to find the distance between the points on a coordinate plane d = square root of (x2 - x1)^2 + (y2 - y1)^2
Midpoint formula The formula used to mind the midpoint between 2 points M = (x1+x2/2, y1 +y2/2)
Segment Bisector A segment, line, ray; plane that intersects a segment at the midpoint
Perpendicular Two lines that intersect at a 90 degree angle (right angle) symbol is an upside down T
Perpendicular Bisector A line, segment, or ray perpendicular to a segment at its midpoint
Parallel Lines Two lines that never intersect symbol: ||
Angle Two rays with a common endpoint
Vertex The common endpoint of an angle
Right angle An angle with a measure of 90 degrees
Acute angle An angle with a measure less than 90 degrees
Obtuse angle An angle with a measure greater than 90 degrees
Straight angle An angle with a measure of 180 degrees
Congruent angles Two angles that have the same measure are congruent
Adjacent angles Two angles that share a vertex and a side
Angle addition postulate If angle ABD and angle DBC are adjacent, then measure of angle ABD + measure of angle DBC = measure of angle ABC
Angle bisector A line or ray that divides an angle into 2 "=" points
Vertical angles Two angles directly across from each other on intersecting lines *always congruent*
Complementary angles 2 angles with measures that sum to 90 degrees "don't have to be adjacent*
Supplementary angles 2 angles with measures that sum to 180 degrees "don't have to be adjacent*
Linear pair Adjacent angles that form a straight line, they are supplementary
An angle is formed by 2 ___ with a common endpoint rays
This common endpoint is called the ___ vertex
Name an angle using ___ letters 3
A ray that divides an angle into ___ _____ ____ 2 congruent angles
Two lines that _____ at a _____ ______ intersect right angle
A line, segment, or ray _______ to a segment is its ______ perpendicular midpoint
Created by: pandabear66*
Popular Math sets




Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!
"Know" box contains:
Time elapsed:
restart all cards