Classifying Triangles

Sometimes understanding the differences between triangles can get a little difficult. There are two key parts to classifying a triangle; angles and sides. The three angles we use to classify a triangle are acute, obtuse, and right. The three side classifications we use are equilateral, isosceles, and scalene. First, it is important to know what all these words mean.

Acute triangle - ALL angles are less than 90°

Obtuse triangle - One angle greater than 90° but less than 180°

Right triangle - Exactly ONE 90° angle

Equilateral triangle - ALL three sides are the same length (Congruent)

Isosceles triangle -At LEAST two sides the same length (Congruent)

Scalene triangle - ALL sides are different lengths

We created a cutout that helped us understand the classification of each triangle. We folded in the sides to create three folds. We then made several cuts to make little windows for each word. We wrote down each definition and then drew a triangle to give a visual. Doing activities like these really help ingrain the information into your brain. I think this is a wonderful activity to do with students because it is easy to understand and easy to construct. 

My Acute Equilateral Triangle

Today, we started our section on triangles, and I was very excited because I feel pretty comfortable identifying and measuring triangles. We did several activities today, but one really stood out to me because it was a fun and engaging way to understand the angles of a triangle. In one of the activities we did, we drew a decently sized triangle on a piece of paper and then we cut it out. We needed to classify our triangle and write the classification on the triangle. After we had finished making our triangles, we then had to tear all three corners off. Believe me when I say that it was the hardest thing for me to do since I had made a beautiful acute equilateral triangle.
However cringeworthy it maybe have been, it was necessary to have one rough edge so you knew which part was the ends of the triangle. After that, we put the ends of the triangle together and it created a straight line. The purpose of this activity was to show that all three angles of a triangle will add up to 180 degrees which is the measurement of a line or a straight angle. I will definitely be using this with the fourth graders I am currently working with as well as in my future classroom. Below are photos of the activity.

Geometry Definitions Chart

So we recently started our chapter on Geometry. I don't really remember too much about geometry, but I do love shapes, especially when paired with art. The fundamental building blocks for ANY subject is definitions. Well, we all know how boring copying down those lengthy definitions are and they never really stick because they hardly make sense when you first see them. Upon starting this lesson we were given a sheet of paper that had a chart with six of the major words we needed to know. On the left side it says, Model, Describe how they are drawn, Named by, Facts, and Words/Symbols.
This really breaks down the definition into more manageable chunks that are easier to comprehend. We were also given a bag that had 30 color-coded pieces of paper that we had to place with the proper word. I really liked this activity because it's hands-on and you're really focusing and absorbing these definitions. I feel more confident going into Geometry fully understanding these definitions. I have attached some pictures of the assignment as well.