Covers topics on Defined and Undefined Terms, Angles and Kinds of Angles According to Measurement

1. Roxanne Joie V.
Deang
BSE Math IV

4. Point
basic element in geometry represented by a
dot (.)
an idea that shows an exact location in
space
no dimension; no length; no width and no
thickness
named using a capital letter

6. Line
set of infinite points extended endlessly or
indefinitely in two directions
represented by a stretch string, edge of a
table, etc.
it has one dimension which is the length
named by one small letter or two capital
letters

7. Name
this
line!
L O V E

9. Plane
set of infinite points extended in four
directions
it has two dimensions – length and width
represented by any flat surface
named by at least three points of the plane
provided that the points must not lie along
the same line

10. Name A
this
plane! R N
K
J
V
D L
M

13. Ray
a part of a line that extends indefinitely in
one direction
named by writing the endpoint first and
then another point on the ray
R O X

15. Angle
formed by two rays with a common
endpoint
 the common endpoint is called the
vertex
 the two rays are called the sides of the
angle

16. Angle
when naming an angle, the letter
designating the vertex should always stand
between two other letters.
an angle can also be named by using a single
letter designating the vertex
B
A
C

17. Angle
angles are
measured in units
called degrees (o)
a protractor is used
to measure angles

20. Right Angle
an angle whose measure is 90o
a small square is usually placed to indicate a
right angle

21. Right Angle
E
D F

23. Acute Angle
an angle whose measure is greater than 0o
and less than 90o

24. Acute Angle
H
G I

26. Obtuse Angle
an angle whose measure is greater than 90o
but less than 180o

27. Obtuse Angle
K
J L

28. Try this!

29. Use the figure to answer each questions below.
B C
D
2 3
A 1 4 E
What kind of angle is each? Write A for Acute, R for Right and O
for Obtuse.
1.) 2 4.) 2+ 3
2.) 4 5.) 2+ 3+ 4
3.) 1+ 2 6.) 1+ 2+ 3

31. 1

32. 2

33. 3

34. 4

35. 5

36. 6