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

A piece of a line with two endpoints; it is named by its endpoints Line Segment A piece of a line with two endpoints; it is named by its endpoints A B AB or BA

Ray A 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

Lines, segments, or rays that cross each other Intersecting Lines, segments, or rays that cross each other

Lines, segments, or rays that intersect at 900 (right) angles Perpendicular Lines, segments, or rays that intersect at 900 (right) angles

(THINK…car on the bridge compared to a boat on the water) 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) How to name this angle: M J K KJM J MJK

The point where 2 rays meet to form an angle Vertex The point where 2 rays meet to form an angle Y Vertex Q N

A point that lies inside the two rays of an angle Interior Point A point that lies inside the two rays of an angle C

A point that lies outside the two rays of an angle 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. B Y These triangles are congruent! X A Z C

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 C B A

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

Prism A 3-D shape with 2 congruent bases; all other faces are rectangles Prisms are named by the shape of their bases Square prism Triangular 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