# Honors Geometry Exam Review I

## 75 terms · The terms, postulates, and theorems. Not done yet.

### Undefined term

A word without a formal definition

### Point

An object with no dimension represented by a dot

### Line

An object with one dimension represented by a line with two arrowheads

### Plane

An object with two dimensions represented by a shape

### Defined term

A term that can be described using known words

### Line segment

A section of a line with a finite distance

### Endpoint

One of the boundaries of a line segment

### Ray

A cross between a line segment and a line, it consists of a line with one endpoint and the other side extending to infinity

### Opposite Rays

Rays lying on either side of the seperation point in a line

### Collinear

Lie on the same line

### Coplanar

Lie in the same plane

### Intersect

Fill in the blank. When two objects _____________, they have at least one point in common

### Intersection

The set of points that intersecting figures have in common

### Postulate

Also known as an axiom, this is a rule that is accepted without proof

### Theorem

A rule that can be proved

### Coordinate

The real number that corresponds to a point

### Distance

Absolute value of the difference between two coordinates

### Between

Fill in the blank. When three points are collinear, you can say that one point is __________________ the other two

### Congruent segments

Line segments that have the same length

### Midpoint

Point that divides a line segement into two congruent segments

### Segment bisector

A point, ray, line, line segment, or plance that intersects the segment at its midpoint

### Angle

Two different rays with the same endpoint

### Acute

An angle with a measure of 0⁰<x⁰<90⁰

### Right

An angle with a measure of 90⁰

### Obtuse

An angle with a measure of 180⁰>x⁰>90⁰

### Straight

An angle with a measure of 180⁰

### Congruent angles

Angles with the same measure

### Angle bisector

A ray that divides an angle into two congruent angles

### Complementary angles

Two angles whose measures sum up to 90⁰

### Supplementary angles

Two angles whose measures sum up to 180⁰

Two angles that share a common vertex or side but have no common interior points

### Linear pair

Two adjacent angles whose non-common sides are opposite rays

### Vertical angles

Two angles whose sides form two pairs of opposite rays

### Convex

No line that contains a side of the polygon contains a point in the interior of the polygon

### Concave

A polygon that is not convex

### n-gon

A term used to name a polygon, where n is the number of the polygon's sides

### Equilateral

In this type of polygon, all sides are congruent

### Equiangular

In this type of polygon, all angles are congruent

### Regular

This type of polygon is both equilateral and equiangular

### Conjecture

Unproven statement based on observations

### Inductive reasoning

Reasoning based on patterns in specific cases

### Counterexample

Specific case that proves a conjecture false

### Conditional statement

Logical statement consisting of a hypothesis and conclusion

### If-then

Form of conditional statement where "If" is the hypothesis and
"then" is the conclusion

### Hypothesis

The "If" part of an if-then statement

### Conclusion

The "then" part of an if-then statement

### Negation

The opposite of the original statement

### Converse

An if-then statement where the hypothesis and conclusion of the original statement are flipped

### Inverse

An if-then statement where the hypothesis and conclusion of the original statement are negated

### Contrapositive

An if-then statement where the hypothesis and conlcusion of the original statement are flipped and negated

### Equivalent statements

Two statements that are both true or both false

### Perpendicular

Two lines intersect to form a right angle

### Biconditional statement

When a conditional statement and its converse are both true, you can conjoin the two statements into this statement using the phrase: "if and only if"

### Deductive reasoning

Reasoning that uses facts, definitions, accepted properties, and the laws of logic to form a logical argument

### Law of Detachment

If the hypothesis of a true conditional statement is true, then the conclusion is also true.

### Law of Syllogism

if Hypothesis P ➡Conclusion Q and Hypothesis Q➡Conclusion R are true conditional statements then Hypothesis P➡Conclusion R is true

If a=b, then a+c=b+c

### Subtraction property

If a=b, then a-c=b-c

### Multiplication property

If a=b, then ac=bc

### Division property

If a=b and c≠0, then a÷c=b÷c

### Substitution property

If a=b, then a can be substituted for b in any equation or expression

### Distributive property

a(b+c) = ab+ac, where a, b, and c are real numbers

### Proof

Logical argument that shows a statement is true

### Two-column proof

Proof with numbered statements and corresponding reasons that show an argument in logical order

### Parallel lines

Coplanar lines that do not intersect

### Skew lines

Non-coplanar lines that do not intersect

### Parallel planes

Planes that do not intersect

### Transversal

Line that intersects two or more coplanar lines at different points

### Corresponding angles

Angles formed by a transversal with corresponding positions

### Alternate interior angles

Angles formed by a transversal that lie between the two lines and on opposite sides of the transversal

### Alternate exterior angles

Angles formed by a transversal that lie outside the two lines and on opposite sides of the transversal

### Consecutive interior angles

Angles formed by a transversal that lie between the two lines and on the same side of the transversal

### Paragraph proof

Proof written in paragraph form in sentences in logical chronological order

### Slope

Ratio of vertical change over horizontal change between any two points on the line

### Slope-intercept form

Form of a linear equation written in y=mx+b