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Index Card. Let’s start our stack of Theorems, Postulates, Formulas, and Properties that you will be able to bring into a quiz or test. Whenever I want you to add to your Theorem or Postulates I will set the background to bright yellow. 12. AB = AC + CB. = 4 + 8. = 12.
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Index Card • Let’s start our stack of Theorems, Postulates, Formulas, and Properties that you will be able to bring into a quiz or test. • Whenever I want you to add to your Theorem or Postulates I will set the background to bright yellow Lesson 1-1 Point, Line, Plane
12 AB = AC + CB = 4 + 8 = 12 The Segment Addition Postulate Postulate: If C is between A and B, then AC + CB = AB. The length of a line segment is equal to the sum of its parts. If AC = 4 , CB = 8 then Example: 8 4 Lesson : Segments and Rays
If numbers are equal the objects are congruent. AB: the segment AB ( an object ) AB: the distance from A to B ( a number ) Congruent Segments Definition: Segments with equal lengths. (congruent symbol: ) Congruent segments can be marked with dashes. Correct notation: Incorrect notation: Lesson 1-2: Segments and Rays
Midpoint Definition: A point that divides a segment into two congruent segments Formulas: On a number line, the coordinate of the midpoint of a segment whose endpoints have coordinates a and b is . Lesson 1-2: Segments and Rays
Midpoint In a coordinate plane for a line segment whose endpoints have coordinates and . The midpoint is given by: . Lesson 1-2: Segments and Rays
Midpoint Formula In a coordinate plane for a line segment whose endpoints have coordinates and The midpoint is given by: . Lesson 1-2: Segments and Rays
Practice • Find the midpoint between (7, -2) and (-4, 8). Lesson 1-2
Segment Bisector Definition: Any segment, line or plane that divides a segment into two congruent parts is called segment bisector. Lesson 1-2: Segments and Rays
The Distance Formula The distance d between any two points with coordinates and is given by the formula d = . Lesson 1-2
d = d = d = The Distance Formula Find the distance between (-3, 2) and (4, 1) Example: x1 = -3, x2 = 4, y1 = 2 , y2 = 1 Lesson 1-2
Practice • Find the distance between (3, 2) and (-1, 6). Lesson 1-2: Formulas
Homework • Pg. 19 # 8, 12, 16, 19, 21 • Pg 20 # 24, 26, 32 • Pg 21 # 52 Lesson 1-2: Formulas