front 1 Reflexive Property  back 1 A Quantity Is Congruent (Equal) to itself.

front 2 Transitive Property  back 2 If two things are equal to a third thing, then they

front 3 Additive Property  back 3 If equal quantities are added to equal quantities then the sums are equal

front 4 Subtraction Prstulate  back 4 If equal quantities are subtracted from equal quantities then the differences are equal.

front 5 Multiplication Postulate  back 5 If equal quantities are multiplied by equal quantities then the products are equal

front 6 Division Postulate  back 6 If equal quantities are divided by equal nonzero quantities then the quotions are equal

front 7 Substitution Postulate  back 7 A quantity and its equal(s) are interchangeable in an expression. If abc=def is given, and ab+de=abc, then ab+de=def would be true. 
front 8 Partition Postulate  back 8 The whole is equal to the sum of its parts.

front 9 Construction Straight line  back 9 Two Points determine a straight line 
front 10 Construction Perpendicular  back 10 From a given point one and only one perpendicular can be drawn to the line. 
front 11 Right Angles  back 11 All Right angles are congruent. All right angles = 90 degrees. Formed by 2 lines perprndicular to each other 
front 12 Straight Angles  back 12 An angle whose sides lie in opposite directions from the vertex in the same straight line and which equals two right angles 
front 13 Congruent Supplements  back 13 If two angles are supplements of the same angle (or of congruent angles), then the two angles are congruent

front 14 Congruent Compliments  back 14 If two angles are compliments of the same angle (or of congruent angles), then the two angles are congruent. Compliments of the same angle or congruent angles are congruent

front 15 Linear Pair  back 15 If two angles form a linear pair,then they are supplementary (m < 1 + m< 2 = 180 Degrees). Two angles that are adjacent (share a leg) and supplementary (add up to 180°) 
front 16 Vertical Angles  back 16 Vertical angles are on opposite sides of the X formed when two lines intersect Vertical Angles are congruent.They are congruent Vertical angles are always congruent, or of equal measure. Both pairs of vertical angles (four angles altogether) always sum to a full angle (360°). 
front 17 Triangle Sum  back 17 The sum of the interior angles of a triagle is 180 Degrees 
front 18 Exterior Angle  back 18 The measure of an exterior angle of a triangle is equal to the sum of the measures of the two nonadjacent interior angles. The measure of an exterior angle of a triangle is greater than either nonadjacent interior angle 
front 19 Base Angle Theorem
 back 19 If two sides of a triangle are congruent, the angles opposite are congruent 
front 20 Corresponding Angles Converse  back 20 If two parallel lines are cut by a transversal, and the corresponding angles are congruent the lines are parallel 
front 21 Corresponding Angles  back 21 If two lines are cut by a transversal, then the pairs of corresponding angles are congruent 
front 22 Alternate Interior Angles  back 22 If two parallel lines are cut by a transversal, then the alternate interior angles are congruent.

front 23 Alternate Exterior Angles  back 23 Formed when two lines are cut by another line (transversal), the pairs of angles formed outside the two lines and on the opposite of the transversal.

front 24 Interiors on Same Side Angles  back 24 If two parallel lines are cut by a transversal,the interior angles on the same side of the transversal are supplemetary.

front 25 Alternate Interior Angles Converse  back 25 If two lines are cut by a transversal and the alternate interior angles are congruent then the lines are parallel

front 26 Alternate Exterior Angles Converse  back 26 If two lines are cut by a transversal and the alternate exterior angles are congruent then the lines are parallel or

front 27 Interiors on Same Side Converse  back 27 If two lines are cut by a transversal and the interior angles on the same side of the transversal are supplementary then the lines are parallelor If two lines and a transversal form sameside interior angles that are supplementary, then the lines are parallel. 
front 28 Acute Angle  back 28 Any angle whose measure is less than 90 degrees. Does not include 0 or 90 Degrees 
front 29 Adjacent Angles  back 29 Angles that share a vertex and that have a side in common. 
front 30 Midpoint  back 30 A point that divides a segment into two congruent segments. The point on that line segment that divides the segment two congruent segments. 
front 31 Perpendicular  back 31 Forming right angles. Right angles measure 90 degrees 
front 32 Postulate  back 32 A geometic statement assumed to be true without proof 
front 33 SameSided Exterior Angles  back 33 Angles on the same side of the transversal, and they’re outside the parallel lines. <7 and <1 also <8 and <2

front 34 SameSided Interior Angles  back 34 If two parallel lines are cut by a transversal, the interior angles on the same side of the transversal are supplementary.

front 35 Transversal  back 35 A line that crosses two parallel lines 
front 36 Vertical Angles  back 36 Congruent anglea formed by two intersectin lines that make an X; the vertical angles are on opposite sides of the X. 
front 37 Segment Addition Postulate  back 37 In the diagram we have AX = 5 and XB = 6. AB = 5 + 6 = 11. 
front 38 Subtraction Property of Equality  back 38 States that when both sides of an equation have the same number subtracted from them, the remaining expressions are still equal.

front 39 Symmetric Property of Equality  back 39 If we have an equation like

front 40 Substitution Poperty of Eqrality  back 40 If I know that two variables both refer

front 41 Converse Conditional Statement  back 41 This form of a conditional statement is obtained by interchanging the hypothesis and conclusion. If it is the first of the month then the rent is due becomes If the rent is due then it is the first of the month 
front 42 Inverse Conditional Statement  back 42 This form of a conditional statement is obtained by negating the hypothesis and negating the conclusion. If it is the first of the month then the rent is due becomes If it is not the first of the month then the rent is not due 
front 43 Contrapositive Conditional Statement  back 43 This form of a conditional statement is obtained by interchanging and negating the hypothesis and conclusion. If it is the first of the month then the rent is due becomes If the rent is not due then it is not the first of the month 
front 44 Syllogism  back 44 An instance of a form of reasoning in which a conclusion is drawn (whether validly or not) from two given or assumed propositions (premises), each of which shares a term with the conclusion, and shares a common or middle term not present in the conclusion (e.g., all dogs are animals; all animals have four legs; therefore all dogs have four legs ).

front 45 Venn Diagrams  back 45 a diagram that shows all possible logical relations between a finite collection of sets.The diagram shows and or or nor relationships 
front 46 Hypothesis  back 46 The "If" part of a statement. A statement that might be true, which can then be tested 
front 47 Conclusion  back 47 The "then" part of a conditional statement. 
front 48 Conditional Statement  back 48 Name for an If...Then statementA compound statement formed by joining two statements with "if" and "then" 
front 49 Statement  back 49 A declarative statement which is either true or false, but never both 
front 50 Negation  back 50 Sometimes in mathematics it's important to determine what the opposite of a given mathematical statement. If a statement is true, then its opposite is false (and if a statement is false, then its opposite is true).

front 51 Conjunction A and B  back 51 A compound statement resulting from the joining of two statements using an AND. Both statements must be true for the conjunction to be true.

front 52 Disjunction  back 52 A compound statement resulting from the joining of two statements using OR.If both statements are false Then the compound is false.Logical OR is also known as logical disjunction. Disjunction literally means "a state of being disjoined". Logical disjunction holds when at least one of the given conditions is true. It is a binary operator which requires at least two operands for its application. 
front 53 Theorem  back 53 A statement of a mathematical fact that can be proved 
front 54 The law of Detachment  back 54 A form of deductive reasoning that is used to draw conclusions from true conditional statements. If p then q is true then p is true and q is true.

front 55 Transitive property of equality:  back 55 if a number is equal to a second number, and the second number is equal to a third, then the first number and the third number are also equal.

front 56 Alternate Exterior Angles  back 56 Defined as two exterior angles on opposite sides of a transversal which lie on different parallel lines.

front 57 Alternate Interior Angles  back 57 two interior angles which lie on different parallel lines and on opposite sides of a transversal.he pair of angles 3 and 6 (as well as 4 and 5) are alternate interior angles. These angle pairs are on opposite (alternate) sides of the transversal and are in between (in the interior of) the parallel lines. 
front 58 Consecutive Interior Angles  back 58 In the figure above, angles 4 and 6 are consecutive interior angles. So are angles 3 and 5. Consecutive interior angles are supplementary. The pairs of angles on one side of the transversal but inside the two lines are called Consecutive Interior Angles. 
front 59 Congruent  back 59 Exactly equal in size and shape. Congruent sides or segments have the exact same length. Congruent angles have the exact same measure. For any set of congruent geometric figures, corresponding sides, angles, faces, etc. are congruent. 
front 60 Concurrent  back 60 Lines or curves that all intersect at a single point. 
front 61 Coincident  back 61 Identical, one superimposed on the other. That is, two or more geometric figures that share all points. For example, two coincident lines would look like one line since one is on top of the other. 
front 62 Contrapositive  back 62 Switching the hypothesis and conclusion of a conditional statement and negating both. For example, the contrapositive of "If it is raining then the grass is wet" is "If the grass is not wet then it is not raining."

front 63 Converse  back 63 Switching the hypothesis and conclusion of a conditional statement. For example, the converse of "If it is raining then the grass is wet" is "If the grass is wet then it is raining."

front 64 Inverse of a Conditional  back 64 Negating both the hypothesis and conclusion of a conditional statement. For example, the inverse of "If it is raining then the grass is wet" is "If it is not raining then the grass is not wet".

front 65 Iff
 back 65 A way of writing two conditionals at once: both a conditional and its converse.

front 66 Corresponding  back 66 Two features that are situated the same way in different objects. 
front 67 Linear Pair of Angles  back 67 A pair of adjacent angles formed by intersecting lines. Angles 1 and 2 below are a linear pair. So are angles 2 and 4, angles 3 and 4, and angles 1 and 3. Linear pairs of angles are supplementary. 
front 68 Parallel Lines  back 68 Two distinct coplanar lines that do not intersect. Note: Parallel lines have the same slope. 
front 69 Straight Angle  back 69 A 180° angle. 
front 70 Transversal  back 70 A line that cuts across a set of lines or the sides of a plane figure. Transversals often cut across parallel lines. 
front 71 Interior Angle  back 71 An angle on the interior of a plane figure.

front 72 Properties of Angle Congruence  back 72 Angle congruence is reflexive, symmetric, and transitive. Here are some examples.
