Creative Math: Lesson on Triangles

I need to say right off, that these lessons are not original and borrowed in part or in entirety from other blogs and websites!

The main resources for this lesson came from: 

Illuminations  - this is a fabulous resource for Math lessons done in a hands on and creative way.

Jimmiescollage  - lots of fantastic ideas for everything, she has put together the Shakespeare Lens as well as the Transitioning to Living Math lens in Squidoo that I mentioned in previous posts.

Daily Life of a Mom - excellent lapbooking ideas for a study on Triangles.

Below is a snapshot of how we used their ideas in our lesson.

We started off using the lesson plan from Illuminations where I asked them questions about what a triangle is, what properties they have like how many sides and angles.

We then took time to build different shapes using triangles based on this worksheet. They built squares, bigger triangles and parallelograms. We also used pattern blocks to see the different ways one could build a triangle. Again, just a fun way to interact with the shapes.

After reviewing what we have discovered about the properties of a triangle, we proceeded to talk about angles and they marked out the angles on the triangle.

They then drew a circle and divided it into quarters and I showed them that they made right angles. Then we looked at a straight line and worked out it was 180 degrees (90+90) and then they worked out that a circle had 360 degrees (180+180) - which they already knew from their previous lesson.

I cut out a variety of triangles in different sizes and had them measure the angles of each triangle with a protractor (acknowledgements to Jimmiescollage for this idea). From this exercise, they discovered that the angles on a triangle are always 180 degrees! They then cut the angles out of a triangle and lay them next to each other to form a straight line! It was cool to see it visually even if they knew it in theory.

We moved onto discussing the different types of triangles.

We talked about the properties of a right angled triangle, equilateral triangles and Isosceles triangles using lapbook pieces from Daily Life of a Mom. I liked that they discovered the properties rather than just being what they are.

In our next activity, I asked them the question if any three lengths could equal the sides of a triangle. I gave them this sheet where they investigated this statement. A list of different lengths were given to them and they had to guess what kind of triangle it would make. The girls then cut the specified lengths out of centimetre grid paper and tried to make the triangles. They found that in some instances they couldn't make a triangle when the sum of the lengths of the two shorter sides were not greater than the length of the longest side. This exercise helped them to understand more clearly the properties necessary to make either an equilateral, isosceles, right angle or scalene triangle.

It was a simple lesson that reinforced what my elder daughter had learnt before while teaching my younger daughter some new terms. As usual Creative Math day was a big hit. Next come the Squares!