Transcript Properties of Lines and Angles PPT

Properties of
Lines and Angles
Vocabulary
A POINT indicates location. A
POINT has no size. You name a
POINT by a capital letter.
A LINE is a series of points that
extend in two opposite directions
without end. You name a LINE
by any two points on the LINE or
a lowercase letter.
A SEGMENT is part of a line with
two endpoints and all the points
in between. You name a
SEGMENT by its endpoints.
Vocabulary
INTERSECTING lines
have exactly one point in
common.
PARALLEL lines are
lines that never
intersect.
PERPENDICULAR lines
are lines that intersect to
form a 90° angle.
Real World Application
When gymnasts or skateboarders do a move that
rotates them in a complete circle around a point,
how many degrees have they moved?
How many degrees do they move if they only turn
from one direction to the other (half of a circle)?
Triangle Discovery Activity
Instructions
1.
2.
3.
4.
Your teacher will pass out triangles to you.
Draw an arc in each corner.
Tear off each angle – watch teacher for instructions.
Match up angles so that the small arc create a large
arc.
What did you learn about the relationship between a
straight line and the interior angles of a triangle?
A plain old triangle
A straight line!
180°
Classifying Angles Review
Measure
Between 0° and
90°
90°
Greater than 90°
but less than 180°
180°
Name
Picture
Vocabulary
SUPPLEMENTARY angles are two angles
whose sum is 180°.
Vocabulary
COMPLEMENTARY angles are two angles
whose sum is 90°.
Vocabulary
ADJACENT angles are angles that share a
common vertex and side.
Vocabulary
VERTICAL angles are formed by two
intersecting lines. They are OPPOSITE each
other. The measures of vertical angles are
EQUAL.
Practice Problem A
Color the vertical angles. Each set should be a different color.
(You will need four colors)
Practice Problem B
Color the pairs of supplementary angles. Each set should be
a different color.
(You will need eight colors.)
Practice Problem C
Color the pairs of complementary angles. Each set should be
a different color.
(You will need two colors.)
10
9
Homework Assignment…
Vocabulary
CONGRUENT angles are
angles with equal measures.
Figure B shows parallel lines
m and n. When a line q
intersects two lines q is called
a TRANSVERSAL. The lines
do not have to be parallel,
but if they are, we know
special properties about the
angles that are formed.
Practice Problem D
Color the alternate exterior angles. Each set should be a
different color.
(You will need two colors)
Practice Problem E
Color the alternate interior angles. Each set should be a
different color.
(You will need two colors)
Practice Problem F
Color the corresponding angles. Each set should be a
different color.
(You will need four colors)