Download Classify by angles: Classify by sides: Classify by angles: Classify by

Name: _______________________
Triangles – Angle Measures of Triangles
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Date: _____________
Class: Pre-Algebra
Sheet # 12-01
Investigation
You will be split into groups of four.
You will have two of each angle measure: 20°, 30°, 45°, 60°, 70°, 90°.
You will put two angles together to form a triangle.
Use your protractor to find the measure of the third angle.
Classify
by angles:
4
Task: In your groups, use your transparency papers
to connect given angles to form a triangle. Use your
protractor to measure third angle. Fill in table.
Classify
by sides:
Classify
by angles:
5
Classify
by sides:
6
1
Refer back to the table above. Compare the sum
of the angle measures. Describe any patterns
that are found.
Classify by angles:
Classify by sides:
7
2
Can the angle measures 20°, 70° and 60° form a
triangle? Explain. Use your transparency papers
to check your answer.
8
3
Two angles of a triangle are 40º and 80 º. Find
the measure of the third angle of the triangle.
A 30°
B
60°
C
80°
D
120°
A right triangle has a 35° angle. Find the
measure of the other two angles.
A 55° and 90°
B
25° and 90°
C
135° and 90°
D
35° and 90°
If two angles of a triangle measures 43° and 48°,
the triangle is
A
obtuse
B
isosceles
C
acute
D
right
9
What is the measure of angle x in the figure
below?
14
Find the value of x in
each triangle.
PART A
10
What is the measure of angle x in the figure
below?
PART B
11
What is the measure of angle x in the figure
below?
PART C
PART D
12
A triangle is used in the game of pool to
rack the pool balls. Find the missing
measure in the triangle.
PART E
13
Determine whether each
statement is sometimes, always, or never
true. Justify your response.
PART A A triangle can contain more than one
obtuse angle.
15
Find the measure of
each angle.
PART B A triangle can contain more than one
right angle.
PART C An equiangular triangle is acute.
mA 
mB 
mC 