Vocabulary Points, lines, planes, segments. Point Examples: A B Point C is 1 inch off the face of this screen C.

Vocabulary

Points, lines, planes, segments

Point

• Examples:

A

B

Point C is 1 inch off the face of this screen

C

Line

• Examples:

AB

C

D

E

Space

• Example: (look around…3D view of everything in room)

Collinear Points

• Example:

MN

P

WY

Z

X

Plane

• Example:

Coplanar Points

• Example:

Postulate

• Example:

Through any two points there is exactly one line.

This is accepted to be true.

Segment

• Examples:

G

H

L

J

K

Ray

• Examples:

Parallel

• Examples:

ab

n

m

Skew

• Examples: (Look where floor meets wall in back of room, now look where two walls meet near door.)

x

y

z

This line is in front

This line is in back

The red and green lines will never touch.

Congruent

• Examples:

Theorem

• Example:

A2+B2=C2

Can be proven to be true.

Conjecture

• Form an opinion or supposition about (something) on the basis of incomplete information.

• Example: It rained three days in a row, it more than likely will rain again today.

Acute

• .

78⁰

89⁰

Right

• .

90⁰

Obtuse

• .

133⁰35⁰

Theorem

• An idea that has been demonstrated as true or is assumed to be true.

• Example: Pythagorean triples; A2 + B2 = C2 • 32 + 42 = 52

• 9 + 16 = 25• 25 = 25• True

Congruent

• The same shape and size.

Complementary Angles

• 1 + 2 = 90⁰

12

1

2

Supplementary Angles

• 1 + 2 = 180⁰

1 2

12

Vertical Angles

• 1 = 3 AND 2 = 4

2

13

4

Adjacent Angles

• .

Linear Pair

• .

Segment Bisector

• Cuts segment in half

b

a

c

d

Angle Bisector

Perpendicular Bisector

• .