1. Ruler & Protractor Postulates
Santucci’s Starter:
1. Complete with sometimes, always, or never:
Two lines that lie in parallel planes are ______ parallel.
Two lines in intersecting planes are ___________ skew.
2. Explain the difference between skew and parallel lines.

2. Ruler & Protractor Postulates
Ruler Postulate
Find AB
Protractor Postulate

3. Distance on the x-y plane (1-7)
Ex: Find the distance between (3, -4) and (5, 6) in simplified, exact form

4. Segment Addition Postulate
If A, B, and C are collinear and B is between A & C then
AB + BC = AC
AC = 60 find x and AB

5. Angle Addition Postulate
If <AOC and <COD are adjacent angles, m<AOC + m<COD = m<AOD

6. EXAMPLE
m<AOC = x, m<COD = 5x + 4 and m<AOD = 70
find x and m<COD

7. 56–58. Answers may vary. Samples are given.
GEOMETRY LESSON 1–4
25. 90; right
; obtuse
27. 34
28. 70
29. Q
30. 6
31. –4
32. 1
33. –2.5, 2.5
34. –3.5, 3.5
35. –6, –1, 1, 6
37–41. Peer edit your work.
55. about 42°
56–58. Answers may vary. Samples are given.
56. 3:00, 9:00
57. 5:00, 7:00
58. 6:00, 12:32
61. 30
63. 40
64. 80
1-4

8. Midpoints
M is the midpoint of RT. Find RM, MT, and RT.

9. Try it!
If B is between A and C, find the value of x and the measure of BC
AB = 3(x + 7)
BC = 2(x – 3)
AC = 50

10. Using more algebra
If B is between A and C, find the value of x and the measure of BC
AB = x2 + 20
BC = 3 - x
AC = 17

11. Bisectors QN bisects DNB. 1. Construct AC so that AC NB.
2. Construct the perpendicular bisector of AC.
3. Construct RST so that RST QNB.
4. Construct the bisector of RST.
5. Find x.
6. Find m DNB.

12. Starters: Find x if ray WR is an angle bisector
Ray RT bisects <ARF. m<FRT = 2x+10, m<ARF = 8x+4
Draw a labeled diagram then find x and m<ART.
When done pick up handout & peer edit hw.

13. HW Answers p. 32
82. C
83. F
84. D
85. H
79 and 167
87. never
88. never
89. always
90. never
91. always
92. always
93. always
94. never
70. a. 19.5
b. 43; 137
c.Answers may vary. Sample:
The sum of the measures S/B 180.
71. y = 15; AC = 24,
DC = 12
72. ED = 10, DB = 10,
EB = 20
75. 12; m AOC = 82,
m AOB = 32,
m BOC = 50
76. 8; m AOB = 30,
m BOC = 50,
m COD = 30
77. 18; m AOB = 28,
m BOC = 52,
m AOD = 108
78. 7; m AOB = 28,
m BOC = 49,
m AOD = 111

14. HW Answers p. 46
18. (4, 2)
; (–2.5, 3)
42.
ST = (5 – 2)2 + (–3 – (–6))2 =
9 + 9 =
TV = (6 – 5)2 + (–6 – (–3))2 =
1 + 9 =
SW = (5 – 6)2 + (–9 – (–6))2 =
9 + 9 =
No, but ST = SW and TV = VW.
The midpts. Are the same, (5, 4). The diagonals bisect each other.