GEOM 2 | Lesson 1 | Explore

Consider following questions:

Can you name at least three different types of triangles?
How would define a triangle to an elementary school student?
How do you think different triangles get their names?

If we have three pieces of wire of different lengths will those pieces of wire ALWAYS create a triangle?

Let’s check it out.  Use the DESMOS program to create triangles using lengths of 3, 4, 5, 6, 8 and 10 units.   As you create different lengths record your results in a table similar to the  one below.   Download the table:  Triangles

1) Use the three smallest measurements (of different size), and see if these can form a triangle.

2) Choosing 3 different measurements each time, keep attempting to make triangles and record your attempts. (You should be recording attempts that do and do NOT work!)

Write down the measurements of each side Could a triangle be formed? What is the largest angle type?
small medium large yes no acute right obtuse

Once completed, compare the sides that formed a triangle, and those that did not. What did you notice about the sum of two sides as it relates to the third side?

From the data above,  make a conjecture.


Go to Watch (Triangle Inequality)