```MJ2
Bellwork
 Draw the triangles and find the value
of x
1.
2.
x&deg;
34&deg;
56&deg;
53&deg;
x&deg;
Assignment Review
Reminder:
 Your Triangle Poster is Due on _________
poster is handed in on ___________
 Unfortunately, If the poster is not handed in
by ________ I will give you a zero (0) as I
do not accept late assignments!
Before we begin…
 For the past couple of days we have
been studying angles and triangles…
 Today we will look at quadrilaterals…
 Raise your hand if you know what a
 Correct…a quadrilateral is a closed
figure with 4 sides and 4 angles…
 Raise your hand if you can name
some examples…
Objective
 Students will classify and find the
missing angle measure of
use the name that best describes it…
 That means we all need to have the
same understanding of the
characteristics of each type of
 Please copy the vocabulary on the
next slide…
Vocabulary
 Quadrilateral – any 4 sided, 4 angle figure
 Trapezoid – a quadrilateral with one pair
of parallel sides
 Parallelogram – a quadrilateral with
opposite sides parallel and opposite sides
congruent
 Rectangle – a parallelogram with 4 right
angles
 Square – a parallelogram with 4 right
angles and 4 congruent sides
 Rhombus – a parallelogram with 4
congruent sides
 When viewing pictures of quadrilaterals
there are 2 types symbols that you need to
be aware of
 The hash mark (/) means the sides are
congruent. If multiple sides are congruent
you will see 1 or 2 hash marks
 The arrow () indicates that the sides are
parallel. If multiple sides are parallel you
will see 1 or 2 arrows.
 Lets look at some examples…
Examples
Square: 4 right angles &amp; 4
congruent sides
Trapezoid – 1 set of parallel
sides
Missing Angle Measurements
 All the angles in any quadrilateral
equal 360&deg; .
 To find the missing measure use the
same process as finding the angles of
a triangle.
1. Add up the given angles and subtract
from 360&deg; .
2. Lets look at an example…
Example
Before you begin…look
at angle x.
Will it be &gt;90&deg;, &lt;90&deg;,
or =90&deg; ? Why?
108&deg;
55&deg;
x&deg;
59&deg;
Example
 Correct…because x is an
obtuse angle it will be
greater than 90&deg;
 The reason you look at
that is to make sure that
reasonable…so if you get
equal to 90&deg;, you have to
question it!
108&deg;
55&deg;
x&deg;
59&deg;
Example
 To find the missing measure
55&deg;
subtract from 360&deg;.
360-(108+55+59)=x
360 – 222 = x
138 = x
Therefore, x = 138&deg;
108&deg;
x&deg;
59&deg;
 In the notes section of your notebook
draw the figure and solve for x
x&deg;
113&deg;
Summary
 In the notes section of your notebook
summarize the key concepts covered
in today’s lesson
 Today we discussed
 The types of quadrilaterals – you will see
this on a test!
 How to find the missing angle of a