| A | B |
|---|
| Diameter | The distance across a circle through its center |
| Point | Undefined term named with a capital printed letter |
| Line | Undefined term named by a lower case script letter |
| Plane | Undefined term named by an upper case script letter |
| Postulate | An axiom |
| Congruent | Same size and shape |
| Equal | Same size |
| Similar | Same shape, proportional size |
| Theorem | A true statement that follows as a result of other true statements |
| Right Angle | =90 degrees |
| Linear Pair Postulate | Linear Pairs are supplemental |
| Parallel Lines | The same distance apart, never intersecting |
| Perpendicular Lines | Intersecting to form 4 right angles |
| Skew Lines | Not parallel, but never intersecting |
| Transversal | Any line that intersects 2 others in distinct points |
| Point | The intersection of 2 lines |
| Solve an equation | Find the value of the variable that makes a statement true |
| Slope | Steepness |
| Rise Over Run | Slope |
| Change in Y over Change in X | Slope |
| Rate of Change in a Graph | Slope |
| Change in Y | Rise |
| Change in X | Run |
| Line Segment | All the points between the endpoints |
| Ruler Postulate | Put one endpoint on zero and the other can be on a positive real number |
| Origin | (0,0) |
| Segment Addition Postulate | A is between B & C and BA + AC = BC |
| Pythagorean Theorem | a^2+b^2=c^2 |
| Distance Formula | Used to find length |
| Circumference | The perimeter of a circle |
| Line | The intersection of 2 planes |
| Polygon | A closed plane figure with line segments for sides |
| Regular Polygon | Equilateral, Equiangular Polygon |
| Equilateral | Same length sides |
| Equiangular | Same size angles |
| Area of a Triangle | 1/2bh |
| Area of a Rectangle | bh |
| Area of a Square | side^2 |
| Area of a Circle | Pi*r^2 |
| Circumference of a Circle | d*Pi |
| Diameter | 2r |
| Bisect | Cut into 2 equal parts |
| Midpoint | A point that bisects a segment |
| Acute | >0 degrees and <90 degrees |
| Obtuse | >90 degrees and <180 degrees |
| Reflex | >180 degrees and <360 degrees |
| Supplementary | sums to 180 degrees |
| Complementary | sums to 90 degrees |
| Adjacent Angles | Sharing 1 ray but no interior points |
| Circumference | 2Pir |
| Justify | provide reasoning and/or proof |
| Explain | show reasoning |
| Evaluate | Find the value of an algebraic expression for a given value of the variable |
| Linear Pair | Adjacent supplementary angles |
| Parallelogram | Quadrilateral with opposite sides parallel |
| Area | Measured in squre units |
| Ray | Part of a line with an endpoint and all points in the opposite direction |
| Concave | Extending a side will interset the interior |
| Convex | No line containing a side also contains an interior point |
| Regular | All sides congruent, all angles congruent |
| Collinear | On the same line |
| Coplanar | In the same plane |
| Between | If AB + BC = AC, then B is this to A & C |
| Endpoint | The beginning of a ray |
| Hypothesis | The part of a conditional statement directly following the word "if" |
| Conditional Statement | Any statement in "if - then" form |
| Converse | The conditional statement made by changing the order of the original hypothesis and conclusion |
| Negation | The opposite of a statement |
| Negation | The word for the symbol ~ |
| Contrapositive | The inverse of the converse of the original conditional statement |
| Inverse | The statement formed by negating the hypothesis and the conclusion of a conditional statement |
| Indirect Reasoning | Using general patterns to form a conjecture |
| Deductive Reasoning | Using facts, properties, defintions, theorems, & laws of logics to form a logical argument. |
| Biconditional | Any statement containing "if and only if |
| Counter Example | Any example that proves a conjecture false |
| Conjecture | Educated Guess |
| Conclusion | The part of a conditional statement directly following the word "then" |
| Addition Property of Equality | + the same thing to each side |
| Subtraction Property of Equality | - the same thing from each side |
| Transitive Property of Equality | If a=b and b=c, then a=c |
| Transitive Property of Congruence | Two objects that are the same size and shape as a third object are the same size and shape as each other |
| Reflexive Property of Equality | A=A |
| Symmetric Property of Equality | if A=B, the B=A |
| Congruent Supplements Theorem | If each of 2 angles are supplemental to a third, they're supplemental to each other |
| Corresponding Angles | Same side of the transversal, same side of each intersected lines |
| Consecutive Interior Angles | Same side of the transversal, inside the intersected lines,  |
| Alternate Interior Angles | Opposite sides of the transversal, inside and on opposite intersected lines |
| Alternate Exterior Angles | Opposite sides of the transversal, outside and on opposite intersected lines |
| Triangle | 3-sided polygon |
| Scalene | No sides congruent |
| Isosceles | 2 sides congruent |
| Equilateral | All sides congruent |
| Acute Triangle | All angles between 0 & 90 degrees |
| Right Triangle | One angle exactly 90 degrees |
| Obtuse Triangle | One angle between 90 & 180 degrees |
| Equiangular Triangle | All angles exactly 60 degrees |
| Interior Angle | "Inside" the rays |
| Exterior Angle | Forms a linear pair with an interior one |
| Corollary | Easily proven using a Theorem |
| Congruent | Same size and shape |
| Corresponding | "Matched up" parts |
| Hypotenuse | Across from the right angle |
| Legs | Forming the right angle |
| Legs | Forming the Vertex Angle |
| Base | Across from the Vertex Angle |
| Base Angles | Also congruent in an Isosceles Triangle |
| Transformation | Changes location and size |
| Congruence Transformation | Changes ONLY location, not size |
| Translation | Slide |
| Reflection | Flip |
| Rotation | Turn |
| SSS Congruence Postulate | Involves all 3 sides |
| SAS Congruence Postulate | Involves the included angle |
| ASA Congruence Theorem | Involves the included side |
| AAS Congruence Theorem | Involves the non-included side |
| HL Congruence Theorem | Only applies to right triangles |
| Triangle Sum Theorem | Involves angles adding up to 180 degrees |
| Exterior Angle Theorem | Involves the 2 remote interior angles |
| Third Angles Theorem | Proves something about the "remaining" angle |
| Isosceles | Equilateral Triangles are also this |
| Equiangular | Equilateral Triangles are also this |
| Equilateral | Equiangular Triangles are also this |
| Base Angles Theorem | Applies to Isosceles Triangles |
| HL Congruence Theorem | a.k.a. SAS for rt. triangles |
| Ninety Degrees | Sum of acute angles in a rt. tri. |
| Supplementary | Interior and adjacent exterior angles |
