1.2 Measuring and Constructing Segments
Measuring and Constructing Segments Coordinate- A point that corresponds to only one number on the number line Postulate (1.2.1) Ruler Postulate: Points on a line can be placed into a one to one correspondence with real numbers on a number line Distance or length (between two points)- the absolute value of the difference of the coordinates
Congruent segments: segments that have the same length Constructions- a way of creating more precise figures
Examples: 2) Construct 2 congruent segments Pg. 14, Check it Out problem 2
Postulate (1.2.2) Segment Addition Postulate- If B is beween A and C, the AB + BC = AC
Examples: M is between K and N. 1) KM = 2x-4 MN= 3x KN= 26 2) KM= 3 NM = 4x+1 KN = 8 3) KM= 2x+1 KN = 34
Bisects- to cut something in half Midpoint- a point that divides a segment in half (into two congruent segments) Segment bisector- a ray, segment, or line that divides a segment in half
Constructing Segment Bisectors Using Paper Using Compass
Examples B is the midpoint of AC 1) AB = 3x + 8 BC = 5x – 26 find x and AC 2) AC= 20x-30 BC = 4x + 2 find x and AB 3) AB = 8x BC = 10x-9 find x and AC