Triangle Interior Angle Sum
Middle School Math
Aligned to Common Core State Standards
Teacher Notes
Insight 360™ is eInstruction’s classroom instruction system that allows you to
interact with your students as they learn, quickly gaining insight into student
understanding during class so you can adjust instruction in real-time during a
single class session.
Use this content, designed specifically for use with Insight 360™, to interact
with your class. This content includes brief instructional material and two
types of activities:
Constructed Response Activity for students to complete as an individual
or a group assignment. Send each Constructed Response Activity to the
Insight 360 iPad Student App.
Assessment Item with CueTag™ for students to respond to via student
response devices. Receive instant real-time feedback and longitudinal
reports.
Measure Angles
To measure an angle, use a protractor. Align the horizontal line on the bottom
of the protractor directly over one side of the angle. The vertex of the angle
should be on the middle of that horizontal line.
This angle measures about 20 degrees.
Triangle Measurement Activity
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Draw any triangle.
Using a protractor, measure the three angles of the triangle.
What is the sum of the angles of your triangle?
What can you conclude?
Triangle Measurement Activity
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Draw any triangle.
Using a protractor, measure the three angles of the triangle.
What is the sum of the angles of your triangle? 180
What can you conclude? The interior angle sum of any triangle is 180.
50
65
65
Interior Angle Sum
The interior angle sum of any triangle is 180.
50
47
104
65
25
29
65
65
Find the missing angle measure.
94
43
Triangle Activity
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Cut three strips of paper of equal length.
Use them to form the sides of a triangle.
Measure the angles of the triangle.
What do you notice?
What can you conclude?
Triangle Activity
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Cut three strips of paper of equal length.
Use them to form the sides of a triangle.
Measure the angles of the triangle.
What do you notice? All three angles measured 60.
What can you conclude? Equilateral triangles are also equiangular.
Which of the following is not possible?
a.
An obtuse right triangle
b.
An obtuse isosceles triangle
c.
An acute isosceles triangle
d.
An acute equilateral triangle
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