Line

A straight path that goes on forever in both directions; it is named by any two points on the line.

Z Y

ZY or YZ

Line Segment

A piece of a line with two endpoints; it is named by

its endpoints

AB

AB or BA

RayA piece of a line with one endpoint and continues forever in the other direction; it’s named by its endpoint and another point on the ray

R T RT

Parallel

Lines, segments, or rays that are always the same

distance apart and NEVER intersect

Intersecting

Lines, segments, or rays that cross each

other

Perpendicular

Lines, segments, or rays that intersect at

900 (right) angles

Skew

Lines, segments, rays that will never intersect because they are in

different planes (THINK…car on the bridge compared to a boat on the

water)

Angle

Two rays that share the same endpoint;

measured in degrees (from 0 to 3600)

KJ

M J

KJM

MJK

How to name this angle:

Vertex

The point where 2 rays meet to form an angle

VertexY

Q N

Interior Point

A point that lies inside the two rays of an

angleC

Exterior Point

A point that lies outside the two rays

of an angle

B

Congruent

Objects that are exactly the same shape and size. When 2 shapes are exactly the same, then their parts (sides, angles, etc.) are the same.

A

B

C

X

Y

Z

These triangles are congruent!

How Many Degrees in a Triangle?

The three angles in a triangle add up to 1800.

So… if angle A is 900, and angle B is 300, then angle C will be 1800-900-300 = 600

A

C

B

How Many Degrees in a Quadrilateral?

The four angles in any quadrilateral add up to

3600.Examples of quadrilaterals:

Circle

A flat, closed curve where every point on the edge is

the same distance from the center

center

Radius

A straight segment drawn from the center of a circle to a point on the outside edge; half the diameter

**There are an infinite # of radii in a circle!

Diameter

A straight segment drawn from one side of a circle to

another THROUGH the center;

twice the radius**There are an infinite # of diameters in a circle!

Circumference

The distance around the edge of a circle found by

multiplying Pi (or Π) by the diameter

C = Π x d

Pi (or Π)

Ratio of the circumference of a circle to the diameter;

Every circle’s circumference divided by

its diameter is Π

Approximately 3.14

PrismA 3-D shape with 2 congruent

bases; all other faces are rectangles

Prisms are named by the shape of their bases

Triangular prism Square prism

Pyramid

A 3-D shape with one base and 3 or more triangular

sides that meet at a vertex; pyramids are named by

their base

Square base, so this

is a square pyramid