Download Geometry – Triangle Angle-Sum Theorem Activity Name: Period

Geometry – Triangle Angle-Sum Theorem Activity
Name: _____________________
Period: _________
1. Draw and cut out a large triangle.
2. Number the angles and tear them off.
3. Rearrange the three corners of the triangle to form one angle.
4. Once you have formed the angle, answer the questions below.
A) What kind of angle is formed by the three smaller angles? What is its measure?
B) Make a conjecture about the sum of the measures of the angles of a triangle.
Proof of Theorem 3-11: Triangle Angle-Sum Theorem
Given:
ABC
Prove:
mA  m2  mC  180
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