Instructions
- Read the definitions and examples carefully.
- Complete each section from left to right.
- Use capital letters when naming points.
- For drawings, use a ruler when possible. Remember:
- A point is shown by a dot.
- A line extends forever in both directions.
- A ray starts at one endpoint and extends forever in one direction.
- An interval is the part of a line between two endpoints. It is also commonly called a line segment.
- Check your answers with the Answer Key when you finish.
1. Learn the Geometry Words
| Figure | Definition | How it looks | How to name it |
|---|---|---|---|
| Point | An exact location with no length or width | A dot labeled with a capital letter | Point A |
| Line | A straight path that extends forever in both directions | Arrows on both ends | Line AB or line BA |
| Ray | A straight path with one endpoint that extends forever in one direction | One endpoint and one arrow | Ray AB: A is the endpoint, and the ray passes through B |
| Interval | The part of a line between two endpoints | Two endpoints and no arrows | Interval AB or interval BA |
Example:
- In
A •──────• B, the figure is an interval AB. - In
A •──────• B──────>, the figure is a ray AB because it starts at A and passes through B. - In
<────── A •──────• B ──────>, the figure is a line AB.
2. Match the Definition
Write the correct letter on each blank.
- A. Point
- B. Line
- C. Ray
- D. Interval
- _____ A straight path that extends forever in both directions.
- _____ A location represented by a dot and a capital letter.
- _____ A straight path with one endpoint that extends forever in one direction.
- _____ The part of a line between two endpoints.
3. Name the Figures
Write the correct name for each figure. Use the words point, line, ray, or interval and the correct capital letters.
A. M •
Answer: __
B. P •────────• Q
Answer: __
C. R •────────• S────────>
Answer: __
D. <──────── T •────────• U ────────>
Answer: __
Hint: For a ray, the first letter names the endpoint. A ray from R through S is named ray RS.
4. Identify the Parts
Look at each figure and answer the questions.
Figure 1
A •────────• B
- What type of figure is shown? __
- What are the endpoints? __
- Name the figure in both possible orders. __
Figure 2
C •────────• D────────>
- What type of figure is shown? __
- Which point is the endpoint? __
- Through which point does the ray pass? __
- Name the ray. __
Figure 3
<──────── E •────────• F ────────>
- What type of figure is shown? __
- Name the figure in both possible orders. __
5. Sort the Names
Place each name in the correct column. Some names may be used more than once if they describe the same kind of figure.
Names to sort: point H, line JK, ray LM, interval NO, point P, ray QR
| Example | Points | Lines | Rays | Intervals |
|---|---|---|---|---|
| Example: point H | point H | line JK | ray LM | interval NO |
6. Label and Draw
Use a ruler and complete each task.
- Draw a point. Label it X.
- Draw an interval with endpoints Y and Z.
- Draw a ray with endpoint G that passes through H.
- Draw a line that passes through K and L.
- Draw two different rays that have the same endpoint, N. Label another point on each ray O and P.
7. Correct the Mistake
Each student made one mistake. Rewrite the answer correctly.
-
A student names the ray shown below as ray BA.
A •────────• B────────>Correct answer: __
-
A student says that the figure below is a line.
C •────────• DCorrect answer: __
-
A student names the point below as point
q.q •Correct answer: __
-
A student says that a line has only one endpoint. Is this correct? Explain.
8. Real-World Geometry Mission
A hiking trail is shown in different ways on a park map.
- Map A shows a trail section that begins at the parking lot and ends at the picnic area.
- Map B shows a trail that begins at the ranger station and continues in one direction beyond the map.
- Map C shows a straight path that continues in both directions beyond the map.
Answer the questions.
-
Which map should use an interval? Explain why.
-
Which map should use a ray? Explain why.
-
Which map should use a line? Explain why.
-
Give two everyday objects or paths that could be modeled by an interval.
9. Optional Challenge
-
Points A, B, and C lie on the same straight path. B is between A and C.
a. Name one interval with endpoints A and B: ____
b. Name one interval with endpoints B and C: ____
c. Name one interval with endpoints A and C: ____
d. Name the line that passes through all three points: ___
-
Explain why ray AB and ray BA are usually different rays.
-
Can a point have an endpoint? Explain your answer.
Answer Key
2. Match the Definition
- B — Line
- A — Point
- C — Ray
- D — Interval
3. Name the Figures
A. Point M
B. Interval PQ or interval QP
C. Ray RS
D. Line TU or line UT
4. Identify the Parts
Figure 1
- Interval
- A and B
- Interval AB and interval BA
Figure 2
- Ray
- C
- D
- Ray CD
Figure 3
- Line
- Line EF and line FE
5. Sort the Names
- Points: point H, point P
- Lines: line JK
- Rays: ray LM, ray QR
- Intervals: interval NO
6. Label and Draw
Answers may look different, but they should include the required labels and markings.
- One dot labeled X.
- A straight path with endpoints Y and Z, with no arrows.
- A straight path beginning at G, passing through H, with an arrow beyond H. This is ray GH.
- A straight path with arrows on both ends passing through K and L. This is line KL or line LK.
- Two rays beginning at N, one passing through O and the other passing through P.
7. Correct the Mistake
- Ray AB. The ray begins at A and passes through B.
- Interval CD. It has two endpoints and no arrows.
- Point Q. Point labels use capital letters.
- No. A line has no endpoints because it extends forever in both directions.
8. Real-World Geometry Mission
- Map A should use an interval because the trail section has two endpoints: the parking lot and the picnic area.
- Map B should use a ray because it begins at the ranger station and continues forever in one direction.
- Map C should use a line because it continues forever in both directions.
- Answers may vary. Examples include a ruler, a table edge, a sidewalk between two buildings, or a road section between two intersections.
9. Optional Challenge
-
a. Interval AB or interval BA
b. Interval BC or interval CB
c. Interval AC or interval CA
d. Line AB, line AC, or line BC
-
Ray AB begins at A and passes through B. Ray BA begins at B and passes through A, so they have different endpoints and point in different directions.
-
No. A point is only a location. It does not extend in any direction, so it cannot have an endpoint.