1 1 Identifying Points Lines and Planes Vocabulary

1. 1 Identifying Points, Lines, and Planes

Vocabulary Point: No dimension. Represented by a dot. Line: One dimension. Line with 2 arrowheads. Extends without end. Plane: Two dimensions. Shape like a floor. Extends without end. Through any three points, not on the same line, there is a plane.

Line segment: Has endpoints. Ray: One endpoint. Other side extends without end. Intersection: Set of points that two figures have in common.

1. 2 Use Segments and Congruence

Vocabulary Postulate or axiom: A rule that is accepted without proof Theorem: Can be proven Congruent segments: Line segments that have the same length

Segment Postulate If B is between A and C, then AB + BC = AC

1. 3 Use Midpoint and Distance Formulas

Midpoint formula: Distance formula:

Examples Find the midpoint between (2, 4) and (-8, 7) Find the distance between those two points

M is the midpoint between AB. A has coordinates (5, 8) and M has coordinates (2, -6). What are the coordinates of B?

1. 4 Measure and Classify Angles

Vocabulary Angle: Two rays with the same endpoint Rays: Sides of the angle Vertex: Endpoint of the angle

Angle Types Acute: Less than 90 degrees Right: Exactly 90 degrees Obtuse: Between 90 and 180 degrees Straight: Exactly 180 degrees

Angle Addition Postulate

Example with algebra What does <CAB equal?

Homework • • • Pg 20 #28, 43, 46, 47 Pg 12 #13 Pg 13 #31 Pg 23 #2, 8 Pg 29 #22, 25 Pg 31 # 49

1. 5 Describe Angle Pair Relationships

Complementary Angles Adjacent Non-adjacent

Supplementary Angles Adjacent Non-adjacent 120 60

Algebra example a = 62°

Linear Pair

Vertical Angles

Algebra Example

1. 6 Classify Polygons

Polygon: A closed plane figure that is formed by three or more line segments that are called sides. Convex: Concave:

Polygons? Convex? Concave?

Number of Sides and Name • • • Triangle: Three Quadrilateral: Four Pentagon: Five Hexagon: Six Heptagon: Seven Octagon: Eight Nonagon: Nine Decagon: Ten Dodecagon: Twelve n-gon: n sides

Equilateral: All sides are congruent Equiangular: All angles are congruent Regular: A convex polygon that is equilateral and equiangular