Unit #1 - Beginning Concepts (Geometry A)

Point

a physical location in space - often shown as a dot labelled with a captail letter.

Straight Line

a continous collection of points that extend forever in two directions

fundamental assumption

through any two distant points only one line can be drawm. It is can be drawn with the two letters and a arrow on top on them.

line segment

a continuous set of point that lie on a line between two points

Collinear

when three of more points that lie on the same line

circle

a set of points that lie the same distance from the center point

Radius

an line segment draw for the center of the circle to any point

diameter

any line segment drawn from one point of the circle to another (has to pass through the middle)

arcs

continuous portions of circles

Ray

a collection of points that lie along a line that have a starting point but no ending point (starting point is called a vertex) (named by heir vertex followed by any point it passes through)

Angle

a combination of two distance ray with a common vertex (staring point) (named by the second letter is the vertex and the other two represent the two other rays that make an angle)

Acute

an acute angle measure between 0 and 90, very pointy and sharp

Obtuse

measures between 90 and 180, looks blunt and dull

Right

has a mesure of 90. It represents one quarter of a full rotation

straight angle

has a measure of 180 - represents exactly one half of a full rotation

Reflex angle

has a measure of 180 and 360 - will not be seen in this quiz

Adjacent Angles

if they are no overlapping and have a ray in common

complementary angle

called complementary because if placed together they would equal 90

supplementary angle

called supplementary because if placed together they would equal 180