Download "Tri" These IVIissing Angles

Name
.
Triangles
"Tri" These IVIissing Angles
-
\
92°
\43°
Every triangle has a total angle measur•eof 180°.
To find the measure of an unknown anc]\B, add the two
known angle measures and subtract th eirsum from 180°.
92°+ 43° =135°
1 •
180°-135° = 45°
X = 45°
i
Find the measure of each missing angle.
A.
/60°\
78°"^~~-—
42
/ z
90
60°\
B.
1
b/
.
<59°
\
c.
i
\
\
49°/
\m°/
© Frank Schaffer Publications, Inc.
18
\ci
98°\
\
FS-10218 Introduction to Geometry
Name
Date
Practice A
Classify the triangle in as many ways a s possible
1.
A
Find the value of
2.
Then classify the triangle in as many ways as
4.
Tell whiether a triangle can have the given angle measures. If not, change
the first angle measure s o that the angle measures form a triangle.
5. 36.9°, 110.4°, 33.7°
6.
62°, 44-°,
4
73-°
4
7. Consider the three isosceles right triangles.
a. Find the value of x for each triangle.
b. What do you notice about the angle measures of each triangle?
c. Write a rule about the angle measures of an isosceles right triangle.
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Resources by Cliapter
f 75
Name.
. Triangles
Interior and Exterior Angles
In the diagram below, angles a, b, and c are interior angles. Angle x is an exterior angle.
The sum of the measures of the interior angles a and b is equal to the measure of the
exterior angle x.
mZa + mZb = mZx
'
Let mZa = 89° and mZb = 37°.
89° + 37° = mZx= 126°
Since Zx and Zc are supplementary angles,
mZc= 180°-126° = 54°
I
Find the missing angle measures. Use what you know about interior, exterior, and
supplementary angles.
1.
S\135°
mZs
mZr
mZg
mZh
mZt
mzr
mZm
mZn
mZk
mZm.
2.
3.
© Franl< Schaffer Publications, Inc.
19
FS-10218 Introduction to Geometry