| A | B |
|---|
| point | an exact location in space |
| plane | a flat surface that extends forever |
| line | a straight arrangement of points that extends forever |
| collinear | points that lie on the same line |
| endpoint | ends a line segment and ray |
| intersect | two lines that meet at one point do this |
| line segement | a part of a line that consists of two endpoints and all the points inbetween |
| ray | part of a line that has one endpoint and extends forever |
| angle | when two rays share a common end-point, this is formed |
| vertex of an angle | the endpoint of an angle |
| side of an angle | the rays of an angle |
| degree | the unit that is commonly used to measure the size of an angle |
| protractor | what you have to use to measure an angle |
| acute angle | an angle greater than 0* and less than 90* |
| right angle | an angle that is 90* |
| obtuse angle | an angle that is greater than 90* and less than 180* |
| straight angle | an angle that is 180* |
| complementary | two angles are this when the sum of their angles is 90* |
| supplementary | when two angles are this their sum is 180* |
| adjacent | two angles that share a common side, but do not overlap each other |
| vertical | when two lines intersect, the angle that are not adjacent |
| perpendicular | two lines that intersect to form right angles |
| parallel | two lines in the same place that do not intersect |
| transversal | a line that intersects two or more lines in the same place at different points |
| alternate interior angles | are interior to the two lines, but on alternate sides of the transversal |
| correspongding angles | are in the same position with respect to the two lines and the transversal |
| polygon | a closed figure formed by joining three or more line segements in a plane at their endpoints, with each line segement joining exactly two others |
| side of a polygon | each line segement in a polygon |
| vertex of a ploygon | each point where two sides meet in a polygon |
| diagonal | a line segement that joins two nonconsecutive vertices |
| regular polygon | a polygon in which all side have the same length and all angles have the same measure |
| scalene triangle | a triangle where no sides have the same length |
| equilateral triangle | a triangle where all three sides have the same length |
| the triangle inequality | the releationship among sides of a triangle |
| acute triangle | a triangle where all angles are acute |
| right trianlge | a trianlge where one angle if right |
| obtuse trianlge | a triangle where one angle is obtuse |
| parralelogram | o quadrilateral with two pairs of parralel sides |
| trapezoid | a quadrilateral with exactly one pair of parralell sides |
| rectangle | a quadrilateral with four right angles |
| square | a quadrilateral with four right angles and four side of equal length |
| line symmetry | when something can be split equally in two down the middle |
| line of symmetry | the line where you split something in two down the middle |
| isosceles triangle | a triangle where at least two sides have the same length |
| rhombus | a quadrilateral with four side of equal length |
