Advertisement Upgrade to remove ads

points that lie on the same line

collinear

points that do not lie on the same line

noncollinear

a mathematical statement that can be proved

theorem

an unproved assumption

postulate

two collinear rays that have a common endpoint and extend in different directions

opposite rays

a pair of angles such that the rays forming the sides of one and the rays forming the sides of the other are opposite rays

vertical angles

a perpendicular segment from a vertex of a triangle to the opposite side

altitude

a line introduced into a diagram for the purpose of clarifying a proof

auxiliary line

a polygon in which each interior angle has a measure less than 180

convex polygon

lying in the same plane

coplanar

the length of the shortest path between two objects

distance

the first and fourth terms of a proportion

extremes

the point of intersection of a line and a plane

foot

the second and third terms of a proportion

means

the point of concurrency of the altitudes of a triangle

orthocenter

the point of concurrency of the perpendicular bisectors of the triangle's sides

circumcenter

the point of concurrency of the medians of a triangle

centroid

an equation stating that two or more ratios are equal

proportion

a quotient of two numbers

ratio

a polygon that is both equilateral and equiangular

regular polygon

two lines that are not coplanar

skew lines

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set