Geometry Lesson 1.1 Vocabulary, Geometry Lesson 1.2 Vocabulary, Geometry Lesson 1.3 Vocabulary, Geometry Lesson 1.4 Vocabulary, Geometry Lesson 1.5 Vocabulary

Collinear

Located on the same line.

Coplanar

Located on the same plane.

Equiangular polygon

is a polygon with all angles equal in measure.

Equilateral polygon

is a polygon with all sides equal in length.

Regular polygon

is a polygon with that has all sides and angles equal in size or measure.

Vertex of an angle

is a the common endpoint of the two rays of an angle.

Angle

is formed by two rays that share a common endpoint provided that the two rays are nonlinear.

Perimeter

is the distance around the outside of the polygon.

Reflex Measure

is the largest amount of rotation about the vertex between the two sides of the angle.

Measure of an angle

is the smallest amount of rotation about the vertex between the two sides of the angle.

Degrees

is the unit of measurement for angles.

Consecutive

means next to.

Line

A straight, continuous arrangement of infinitely many points. It has infinite length and extends forever in both directions.

Acute Triangle

A triangle with all acute angles.

Equilateral Triangle

A triangle with all congruent sides.

Isosceles Triangle

A triangle with at least two congruent sides.

Obtuse Triangle

A triangle with exactly one obtuse angle.

Right Triangle

A triangle with exactly one right angle.

Scalene Triangle

A triangle with no congruent sides.

Consecutive vertices

means vertices that are next to each other.

Perpendicular lines

must be marked

Parallel lines

must be marked.

Perpendicular Lines

must meet at a 90° angle. We use ⊥ to represent it.

Adjacent Angles

must share a vertex and a side.

Intesecting lines

only intersect at one point.

Geometry

The study of earth measure.

Ray

A ray contains an endpoint and all the collinear points on the same side of that endpoint.

Line Segment

Consists of two points called endpoints and all the points between them are collinear with the two endpoints.

Plane

Has length and width but no thickness. It is a flat surface that extends infinitely in both directions.

Point

Has location, but no size.

Decagon

Polygon with 10 sides

Undecagon

Polygon with 11 sides

Dodecagon

Polygon with 12 sides

Triangle

Polygon with 3 Sides

quadrilateral

Polygon with 4 Sides

Pentagon

Polygon with 5 Sides

Hexagon

Polygon with 6 Sides

Heptagon

Polygon with 7 Sides

Octagon

Polygon with 8 sides

Nonagon

Polygon with 9 sides

n-gon

Polygon with n sides

Congruent Line Segments

These have equal measure or equal length.

Midpoint

This is a point on a segment that is the same distance from both endpoints.

Bisect

This means to divide into two equal parts.

Protractor

a geometric tool used to measure angles.

Diagonal

a line segment that connects two non consecutive vertices

Vertical Angles

a pair of angles formed by two intersecting lines that share a common vertex but not a common side.

Linear Pair

a pair of angles that share a vertex and a side. Their non common side must form a line.

Supplementary Angles

a pair of angles that sum to 180°.

Complementary Angles

a pair of angles that sum to 90°.

Points on a line

are collinear.

Skew Lines

are lines that do not intersect and are non coplanear.

Congruent parts of figures

are marked with hash marks.

Lines

are straight.

Good Definition has

classification, differentiation, and can be tested.

Convex Polygons

contains all diagonals inside of the polygon.

Ray

contains an endpoint and all the collinear points on one side of that endpoint.

Congruent Angles

exist if and only if they have equal measure. This is shown using identical markings. This ≅ is the symbol used.

Parallel Lines

exist in the same plane that never meet. We use II to represent it. Need arrows on picture to visually represent it.

Acute Angle

has a measure less than 90°.

Obtuse Angle

has a measure more than 90° but less than 180°.

Right Angle

has a measure of 90°.

Concave polygons

have at least one diagonal outside of the polygon.

Congruent polygons

have the exact same size and shape.

Angle Bisector

if it contains the vertex and divides the angle into two equal parts.

Midpoint

is a point that divides a line segment into two congruent parts.

Counterexample

something that would fit your definition, but is not what you are trying to define.

Vertices of a polygon

the endpoint where the sides meet.

Segment addition

the total is the sum or length of the two parts.