# Geometry Vocab Test 10/10

### Lesson 1-1

Undefined Term- Can only be explained using examples/descriptions

Point- A location; no shape or size

Line- Made up of points; no thickness/width

Plane- Flat surface made up of points; expands indefinitely

Collinear- Points that are on the same line

Coplanar- Points that lie on the same plane

Intersection- When two or more lines cross each other on a plane

Definition/Defined Term- Explained using undefined and/or other defined terms

Space- Boundless, three-dimensional set of all points; can contain lines and planes

### Lesson 1-2

Line Segment- Measurable, two endpoints

Betweeness of Points- There is a real number between two numbers. A<N<B

Between- Example: Point B is between point A and Point C if it lies on the line segment AC

Congruent Segments- One segment that can be mapped onto another segment and both are congruent

Construction- Methods of creating figures without the benefits of measuring tools

### Lesson 1-3

Midpoint- The point halfway to the endpoints of the segment

Segment Bisector- Any segment, line, or place that intersects a segment at its midpoint

### Lesson 1-4

Ray- A part of a line with one endpoint and expands indefinitely

Opposite Rays- By choosing a point on a line it determines two opposite rays

Angle- Formed by two non-collinear rays that have a common endpoint

Side- The rays are called sides of the angles

Vertex- The angles common endpoint

Interior- Referring to all angles on the inside of a shape

Exterior- An angle that is made by the side of the shape and a line drawn out from an adjacent side

Degree- Unit used to measure angles

Right Angle- An angle that is exactly 90 degrees

Acute Angle- An angle that is less than 90 degrees

Obtuse Angle- An angle that is greater than 90 degrees

Angle Bisector- A ray that divides an angle into two congruent angles

### Lesson 1-5

Adjacent Angles- Two angles that lie in the same plane, have a common vertex and side, but no connected interior points

Linear Pair- Adjacent angles with non common sides that are opposite rays

Vertical Angles- Two non-adjacent angles formed by two intersecting lines

Complementary Angles- Two angles with a sum of 90 degrees

Supplementary Angles- Two angles with a sum of 180 degrees

Perpendicular- Lines, segments, or rays that form a right angle

### Lesson 1-6

Polygon- A closed figure formed by a finite number of sides

Vertex of a Polygon- The vertex of each angle

Concave- Some of the lines pass through the interior

Convex- No points of the lines pass through the interior

N-gon- Example: A polygon with 15 sides is a 15-gon

Equilateral Polygon- A polygon in which all sides are congruent

Equiangular Polygon- A polygon in which all angles are congruent

Regular Polygon- A polygon that is convex, equilateral, and equiangular

Circumference- The distance around a circle

Perimeter- The sum of the lengths of the sides of a polygon

Area- The number of square units needed to cover a surface

### Lesson 1-7

Transformation- A function that maps a figure

Preimage- figure being transformed onto a new image

Image- The figure the preimage was transformed into

Isometry- When the preimage and image appear different but are congruent

Reflection- Transformation over the line of reflection

Translation- Transformation that moves all points in the same distance and direction

Rotation- Transformation around a fixed point

### Lesson 1-8

Polyhedron- A solid with all flat surfaces that encloses a single region of space

Face- Flat surface

Edge- Line segments where the faces intersect

Vertex- The point where 3+ edges intersect

Prism- Polyhedron, 2 parallel congruent faces connected by parallelogram faces

Base- Two parallel congruent faces

Pyramid- Polygon base, 3+ triangular faces that meet at a vertex

Cylinder- Solid, circular bases, connected by a curved surface

Cone- Solid, circular base, connected by curved surface to one vertex

Sphere- A set of points in space that are the same distance from a given point

Regular Polyhedron- All faces are regular and congruent polygons

Platonic Solids- The only 5 regular polyhedrons

Surface Area- 2D measurement of the surface of a solid angle

Volume- Measure of the amount of space in an object

### Lesson 1-10

Precision- The clustering of a group of measurements

Absolute Error- Equal to one half the unit of measure

Significant Digits/Figures- The digits of a number that are used to express it to the required degree of accuracy

Accuracy- Refers to how close a measured value comes to the actual desired value

Relative Error- The ratio of the absolute error to the expected measure