1.1 Building Blocks of Geometry

Identifying lines, rays, and segments VOCABULARY Point – usually labeled with an uppercase letter. Describes a specific location in space. Line – points that extend without end in two opposite directions Read as: “line NO or line ON” N O Symbol: NO or ON Ray – has one endpoint and extends without end in one direction. Always when naming give the endpoint first. Read as: “ray AB” B A Symbol: AB

Identifying lines, rays, and segments continued…. Segment – a piece of a line which has two endpoints Read as: “line segment BE or line segment EB” ● ● Symbol: BE or EB B E NOTE: You may have the points at the end of the segment or without. Plane – flat surface that extends indefinitely along its length and width Read as: plane ABC

Identifying lines, rays, and segments continued…. Parallel lines – two different lines that will never intersect no matter how far they extend. C “Line CD is parallel to line YZ.” D Y CD | | YZ Z Intersecting lines – two different lines that meet at a point Q T “Line TS intersects with line PQ” S P

Let’s Do Some Examples! Identify and name the line, ray, or segment. S Q P 1. 2. ● ● 3. N R ray line segment line QP or PQ RS or SR MN or NM

Now You Try! Identify and name the line, ray, or segment. G ray GF or FG F line HJ or JH J H L segment KL or LK K ● ●

Now You Try Continued G H J K L 1. Name 2 rays. HL or GK or JL or JK Name 2 segments that have G as an endpoint. GH and GJ 3. Name a line. GH 4. Name 3 points. Any 3 that includes L or J or K or H or G

Now You Try Continued G A B C D F E 1. Name a pair of intersecting lines. AB and EG or CF and EG 2. Name a pair of parallel lines. AB and CF 3. Name DB and BA another way. BD and AB

Midpoint Midpoint – The midpoint of a segment is the point on the segment that is the same distance from both endpoints. Bisects – The midpoint bisects the segment, meaning that it divides it into two congruent segments M is the midpoint of AB.

1.2 Angles

What is an angle? Angle – An angle is formed by two rays that share a common endpoint Vertex – The common endpoint of the two rays Sides – The two rays Point B is the vertex of angle ABC. The angle may also be referred to as angle CBA, angle B, , or

Angle measures Angle measures – can be anywhere between 0 and 180 degrees. “The measure of angle A is 45 degrees”

Using a protractor Place hole in center of protractor on vertex Align first ray along line on bottom of protractor Use other ray to find angle measure