Geometry Unit1: Segment Relationships Notes
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Unit 1: Segment Relationships After completion of this unit, you will be able to…
• Name lines, rays, and segments
• Define and recognize the following relationships
o Midpoint
o Segment Addition
o Segment Bisector
• Use the relationships to find missing segment lengths
Timeline for Unit 1
Monday Tuesday Wednesday Thursday Friday
26
Visualization
Practice
27
Day 1
Naming Points,
Lines, Rays, and
Segments
28
Day 2
Segment
Relationships
29
Day 2
Segment
Relationships
30
Day 3
Distance Formula
2
No School
3
Day 4
Midpoint Formula
4
Review
5
Unit 1 Assessment
6
Geometry Unit1: Segment Relationships Notes
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Day 1 – Naming Points, Lines, Segments, and Rays Notes
Term Definition Picture Name
Point* A point indicates location
and has no size.
Line*
A line is represented by a
straight path that extends in
opposite directions without
an end.
Plane*
A plane is represented by a
flat surface that extends
without end.
Segment
A segment is part of a line
that consists of two
endpoints and all the points
between them.
Ray
A ray is part of a line that
consists of one endpoint
and extends infinitely in the
other direction.
Opposite Rays
Opposite rays are two rays
that share the same
endpoint and form a line.
Collinear Points on the same line. N/A
Coplanar Points and lines that lie in
the same plane. N/A
*Undefined Term: Basic idea you use to build definitions for other figures
Geometry Unit1: Segment Relationships Notes
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A postulate is an accepted statement of fact.
Postulate 1: Through any two points, there is
exactly one line.
Postulate 2: If two distinct lines intersect, they
intersect in exactly one point.
Postulate 3: If two distinct planes intersect, then
they intersect in exactly one line.
Postulate 4: Through any three noncollinear
points, there is exactly one plane.
Name the following in as many ways as possible:
1. 2. 3.
4. Use the figure at the right to answer the following questions:
a. Are points F, B, and W collinear?
b. Name the plane.
c. Name 4 coplanar points.
d. At what point does line ℓ and 𝐵𝐼↔ intersect?
Geometry Unit1: Segment Relationships Notes
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Types of Lines
Draw and label a figure for each relationship:
a. Point K lies on 𝑅𝑇 ⃡ b. 𝐴𝐵and 𝐶𝐷 intersect at point E.
Day 1 – Naming Points, Lines, and Planes Practice
1. Write the following using correct symbols:
2. Determine if the following are true or false.
Parallel
𝑨𝑩 ⃡ ∥ 𝑪𝑫 ⃡
Lines that do not intersect.
Intersecting
intersectAB CD
Lines that intersect at a
point.
Perpendicular
AB CD⊥ Lines that intersect at a 90
degree angle.
Geometry Unit1: Segment Relationships Notes
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3. Find the intersection of:
4. Determine the following:
5. Name the following:
a. b. c.
d. e. f.
Geometry Unit1: Segment Relationships Notes
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Day 2: Segment Relationships Notes
Think About It: See if you can determine the length of the requested segment. Draw a picture first.
1. C is between A and E. AC = 24 in and CE = 13 in. How long is AE?
2. C is between A and E. CE = 7 in and AE = 23 in. How long is AC?
Segment Addition Postulate: If point B is on𝐴𝐶, and between points A and C, then 𝐴𝐵 + 𝐵𝐶 =𝐴𝐶.
a. Use the diagram to find𝐸𝐹.
b. Write an expression for AC. c. Find the value of z.
Segment Addition
Given:
Conclusion:
Geometry Unit1: Segment Relationships Notes
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Midpoint: Point that divides the segment into two congruent segments.
a. Find 𝐹𝑀 and 𝑀𝐺. b. Find 𝑌𝑀and𝑌𝑍.
c. T is the midpoint of𝑄𝑅. Solve for x.
Segment Bisector: A line, line segment, or ray that divides the line segment into two line segments of equal
length.
a. Find 𝐶𝐵 and 𝐴𝐵.
b. Determine if you have enough information to determine if 𝑃𝐶is the
segment bisector of 𝐴𝐵. Explain why or why not.
Midpoint
Given:
Conclusion:
Segment Bisector
Given:
Conclusion:
Geometry Unit1: Segment Relationships Notes
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Day 2: Segment Relationships Practice
Find the measure of the stated segment.
1. 2. 3.
4. 5. 6.
7. If RS = TU, ST = 19, RU = 33
a) Find RS
b) Find SU.
8. In the diagram, points V, W, X, Y, and Z are collinear. VZ = 52, XZ= 20, and WX = XY = YZ. Find the indicated
lengths.
a. WX d. VW
b. VX e. WZ
c. WY f. VY
9. M is the midpoint of JL. Find JM. 10. Line l is the segment bisector of PQ . Solve for x.
Geometry Unit1: Segment Relationships Notes
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11. Solve for x. Then determine the length of AC. 12. How long is BC?
13. If U is between T and B, TU = 4x – 1, UB = 2x – 1, and TB = 5x, determine:
a. x = ______
b. TU = ______
c. UB = ______
d. TB = ______
Geometry Unit1: Segment Relationships Notes
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Day 3 – Distance Formula
How would you find the distance between the coins and beads?
The Distance Formula allows you to find the distance between two points. The subscripts (x1, y1) only indicate
that there is a first and second point. However, whichever point is first or second is up to you.
Distance Formula: 𝑑 = √(𝑥2 − 𝑥1)2 + (𝑦2 − 𝑦1)2
1. Find the distance between (1, -2) and (-3, 6). 2. Find the distance between (-2, -3) & (-4, 4).
-8 -6 -4 -2 2 4 6 8
-8
-6
-4
-2
2
4
6
8
-8 -6 -4 -2 2 4 6 8
-8
-6
-4
-2
2
4
6
8
Geometry Unit1: Segment Relationships Notes
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Day 3: Distance Formula Practice
Problem 1: Find the distance between the following points. Round to the nearest tenth.
a. (-4, 2) and (2,-1) b. (-2, -3) and (-2, 4) c. (3, 2) and (5, -2)
Problem 2
• Your house is located 3 blocks east and 4 blocks north.
• Town Center Mall is located 1 block west and 5 blocks north.
• Six Flags is centered at the 5 blocks west and 1 block south.
• Iowa Aquarium is located 6 blocks east and 4 blocks south.
A. Plot your house. Label it was Point A. What is the ordered
pair? _______
B. Plot Town Center Mall. Label it as point B. What is the
ordered pair? _________
C. Plot the Six Flags. Label it as point C. What is the ordered
pair? _________
D. Plot Iowa Aquarium. Label it as point D. What is the ordered pair? _________
E. Connect all four points.
Using the distance formula, find the distance (show all your work). Round to the nearest tenth.
F. AB G. BC H. CD I. AD
How many blocks did you travel all together if you left your house to go to the mall, then Six Flags, and then the
Iowa Aquarium?
-8 -6 -4 -2 2 4 6 8
-8
-6
-4
-2
2
4
6
8
Geometry Unit1: Segment Relationships Notes
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Day 4: Midpoint Formula Notes
How would you find the midpoint between the following points?
a. Midpoint of 𝐴𝐷 = _____ b. Midpoint of 𝐴𝐷 = _____
c. Midpoint of 𝐶𝐹 = _____ d. Midpoint of 𝐹𝐵 = _____
The Midpoint Formula allows you to find the midpoint or center between two points.
Midpoint Formula: (𝑥1+𝑥2
2,𝑦1+𝑦2
2)
1. Find the midpoint between (1, -2) and (-3, 6).
2. Find the midpoint between (6.4, 3) and (-10.7, 4).
-8 -6 -4 -2 2 4 6 8
-8
-6
-4
-2
2
4
6
8
Geometry Unit1: Segment Relationships Notes
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3. M is the midpoint of segment AB. The coordinates of A are (-2, 3) and the coordinates of M are (1, 0). Find
the coordinates of B.
4. B is the midpoint of segment AC. The coordinates of A are (-10, 4) and the coordinates of B are (-2,4). Find
the coordinates of C.
-8 -6 -4 -2 2 4 6 8
-8
-6
-4
-2
2
4
6
8
-8 -6 -4 -2 2 4 6 8
-8
-6
-4
-2
2
4
6
8
Geometry Unit1: Segment Relationships Notes
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Day 4: Midpoint Formula Practice
Problem 1: Troop 175 is designing their new campground by first
mapping everything on a coordinate grid. They have found a
location for the mess hall and for their cabins. They want the
bathrooms to be halfway between these two. What will be the
coordinates of the location of the bathrooms?
Problem 2: You and a friend go hiking. You hike 3 miles north and 2 miles
west. Starting from the same point, your friend hikes 4 miles east and 1 mile
south. If you and your friend wanted to meet for lunch, where could you
meet so that both of you hike the same distance?
sProblem 3: Determine the other endpoint given one of the endpoints and the midpoint.
a. Endpoint (0, 3) and Midpoint (3, 5) b. Endpoint (-2, 5) and Midpoint (4, -1)
Problem 4: Points P(-4, 6), Q(2, 4) and R are collinear. One of the points is
the midpoint of the segment formed by the other two points. What are the
possible coordinates of R?