1. Isabel Rivera Galicia

2. A point can be
described as a location
in space. Represented
by a dot and is named
by writing a capital letter
next to the dot.
POINT

3. LINE
A line is a straight row
of points that goes on
forever in both
directions. A line is
named by a minuscule
letter
r
s

4. TYPES OF LINES
•Broken Line: we combine various segments in zigzag
•Wavy Line: we combine semicircular arcs together
•Mixed Line: we combine straight and curve lines

5. A line segment is a piece of a line
that has two endpoints.
It is named for its endpoints. The
segment with endpoints A and B
shown to the right is named:
SEGMENT

6. Lines that are on the
same plane, but that
never intersect
(cross).
PARALLEL LINES
s
r

7. Lines that intersect
(cross)
INTERSECTING LINES

8. An angle is made up of
two lines that start at a
common endpoint. The
common endpoint is
called the vertex.
Named:
ANGLE

9. Angles can be
measured in degrees.
The symbol for degrees
is a small raised circle °

10. Acute angles – measure less than 90°
Right angles – measure exactly 90°
Obtuse angles measure more than 90°
but less than 180°
Straight angles measure exactly 180°
CLASSIFYING ANGLES

11. An angle of 90° is called a
right angle. To show that an
angle is a right angle, we
draw a small square at the
vertex.
RIGHT ANGLE

12. Acute angles measure less
than 90°
ACUTE ANGLE

13. An obtuse angle measures
more than 90° but less than
180°
OBTUSE ANGLE

14. Two lines are called
perpendicular lines if
they intersect to form
a right angle.
PERPENDICULAR LINES

15. Two angles are called
complementary angles if the
sum of their measures is
90°. If two angles are
complementary , each
angle is the complement of
the other.
COMPLEMENTARY ANGLES

16. Two angles are called
supplementary angles if the sum
of their measures is 180°
SUPPLEMENTARY ANGLES

17. If two figures are
identical in both
shape and size
then they are
congruent
CONGRUENT FIGURES

18. If two figures have
the same shape
but different sizes
then they are
similar
SIMILAR FIGURES