UNDIFINED TERMS

1. LESSON 1
GEOMETRY

2. Undefined terms in
GEOMETRY.
- Words that do not require
formal definition.
- In geometry, there are
three undefined terms.

3. Three undefined terms
• POINT
• LINE
• PLANE

4. POINT
- A point has no dimension
or actual size, thus it has
no length, no size, and no
height or thickness.
- A point is usually named
with a capital letter
⋅A ⋅B ⋅C

5. LINE
- A line has infinite length, no
width and no height and it
extends to one dimension
only.
- A line is named by a single
lower case letter or by any
two points which lie on it.

6. PLANE
- A plane has two
dimension and it extend
indefinitely in all.
direction. It has infinite
length, width, but no
height.

7. A plane is named by a
single letter ex.( plane m)
under the concept of
plane, there is a concept
of POLYGON.

8. POLYGON
Is a closed plane figure
formed by connecting three
or more segment at their
endpoints.

9. Common types of polygon
TRIANGLE - 3 sides
QUADRILATERAL - 4 sides
PENTAGON - 5 sides
HEXAGON - 6 sides
HEPTAGON - 7 sides
OCTAGON - 8 sides
NONAGON - 9 sides
DECAGON - 10 sides
UNDECAGON - 11 sides
DADECAGON - 12 sides

10. ACTIVITY 1:
Determine whether each
of the following suggest a
point, a line, or a plane.

11. 1. The corner of the room.
2. The intersection of the
celling and the wall.
3. One of the guitar strings.
4. The side of the box.
5. The tip of your finger.

12. 6. The shadow
7. The stars in the sky
8. The laser beam
9. The parking lot
10.The horizon