Transcript 1.2 Measuring and Constructing Segments

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
KM  MN
• 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
AC
BC = 10x-9
find x and