Activity: To Triangle or Not to
Triangle
Part 1  Making Triangles
Below are 12 line segments (or straws) of various length. Make as many
unique triangles as you can using these segments.
After you make your triangles, record them in the table below.
length A

length B

length C

What kind of triangle is it?  
1  
2  
3  
4  
5  
6 
length A

length B

length C

Why is this an untriangle?  
1  
2  
3  
4 
length A

length B

length C

Triangle
(T) or untriangle (U)? 
Explain why T or U?  
a  2  3  4  
b  8  4  2  
c  6  6  6  
d  7  4  3  
e  3  6  3  
f  8  6  6  
g  2  3  2  
h  2  5  2  
i  8  7  6  
j  3  4  5 
2. How about if all the segments are the same length? Can you always
make a triangle? What is this triangle called?
3. Explain when it is possible for you to make a triangle with three
segments.
4. Explain when it is NOT possible for you to make a triangle with
three segments.