1. Lesson 3 Segment measure and segment bisector

2. Two segment with the same length are congruent () segments.    
AB = CD (in words, the length of AB is equal to the
length of CD)
AB  CD (in words, segment AB is congruent to segment CD)

3. AC = AB + BC Segment Addition Theorem
Ex. 1 Use the diagram to find the length of AC.
AC = AB + BC Segment Addition Theorem
AC =
AC = 20 units

4. Ex. 2 Use the diagram to find ST.

5. Ex. 3 Using algebra find the value of x using the diagram
Ex. 3 Using algebra find the value of x using the diagram. Also find the lengths of AB and CB.

6. A midpoint of a line segment is a point that divides the segment into two congruent segments.
Ex. 1 Point M is the midpoint of AB. Find AM and MB.
We say that M is the
midpoint of AB.
AM  MB
AM  MB Definition of Midpoint
AM + MB = AB Seg add thrm
x + x = 24cm
2x =24
x = 12cm

7. Ex. 2 Point P is the midpoint of RS. Find PS and RS.
RP PS
= 7 cm def of midpoint
RS = RP + PS seg add thrm
RS = 7cm + 7cm
RS= 14 cm

8. A segment bisector is line segment, ray, line or plane that intersects (crosses) a line segment at its midpoint. To bisect a line segment means to divide the segment into two congruent segments.
CD is the bisector of
AB.
AM  MB

9. AM MB def of midpoint or def of 5x = 35 x = 35 5
Ex. 3 Line l is a segment bisector of AB. Find the value of x.
AM MB def of midpoint or def of
seg bisector
5x = 35
x = 35 5
x = 7cm

10. Ex. 4 Find the coordinates of the midpoint GH. a) G(4, 0), H(-3, -1)=
Ex. 4 Find the coordinates of the midpoint GH.
a) G(4, 0), H(-3, -1)
M = = =

11. A(5, -4) and B (7, -6)
(12/2, -10/2) = (6, -5)

12. Class work Page 31#1– 6, 13-16 Page 32 #22-28 Omit #26
Pg. 56 – 57 # 2 – 7, 16 – 29
Pg 56 #11-14
Pg 57 # 30, 32, 34
Pg 59 #42, 44