In this activity, students investigate properties of triangles by randomly generating possible side lengths for triangles. They learn to determine if three line segments can form a triangle. They also learn to classify triangles as acute, obtuse, right, scalene, isosceles, and equilateral triangles. They gain an understanding of the Pythagorean theorem.

Before the Activity

See the attached PDF file for detailed instructions for this activity

Print pages 13 - 18 from the attached PDF file for your class

During the Activity

Distribute the pages to the class.

Follow the Activity procedures:

Randomly generate 3 numbers between 1 and 6 using the roll dice program on the calculator

Use the three numbers as side lengths, cut straws to form these lengths and create a triangle

Keep a tally of the three numbers that could be used to make triangles and those that could not make a triangle

Classify triangles as equilateral if all sides are congruent, as isosceles if two sides are congruent, and as scalene if no two sides are congruent

Classify the triangles as acute if all angles of the triangle are below 90 degrees

Classify the triangle as obtuse if triangle has an angle greater than 90 degrees and has 2 acute angles

Classify triangles as right triangles if the triangle has an angle of 90 degrees and two acute angles

Test for a Pythagorean triplet using the side lengths of different triangles and find the right, acute, and obtuse triangles

Combine class data and create a list of all triangles (28 triangles) possible with a side of 1", 2", 3", 4", 5", and 6"

Use the triangle inequality rule to test the triangles

Classify the triangles by their sides and angles

After the Activity

Students will complete the Worksheet and analyze the results.

Review student results:

As a class, discuss questions that appeared to be more challenging