Triangles

Nico and Nia are having lunch at their favorite restaurant, Three Sides Cafe. “I am SOOO hungry, Nia!” “MEEEE TOOOO!” "“Everything looks delicious!” “How are we going to choose what to eat?” " We can order the Three Sides Special." "What is the Three Sides Special?" "It is any food on the menu that is a triangle shape!" "But how will we know which food is a triangle?" We can help Nico and Nia order their lunch by finding foods that are in the shape of Triangles A triangle is a shape. Shapes are two-dimensional figures that we can name based on their properties. Properties are characteristics that a shape MUST HAVE to be called that particular shape.

Let's look at a triangle. The properties of a triangle are that it must be a closed shape that has three sides and three corners or vertices. Shapes must have particular properties to be called that shape, however, there are some things that do not matter. When deciding which shape a figure is we might notice other things but they don't always have to be the same. For example, the SIZE might be different. "A triangle can be big, big, BIG!" "or a triangle can be small,small, small." The colour might also be different. Triangles can be ANY colour!

Triangles can also face in many different directions or orientations.

Let's identify some triangles! Is this a triangle? Start by counting the sides. It has one, two, three sides. Now count the corners or vertices. It has one, two, three vertices. Yes, this shape is a triangle! How about this shape? Is this shape a triangle? Start by counting the sides. One, two, three, FOUR. Wait a minute, this shape has FOUR sides! Since we know that triangles MUST have three sides, we know that this is NOT a triangle! Let’s try ONE more! Count the sides. Count the vertices. Yes, this is a triangle because it has all of the necessary properties. Now that we know all the properties of a triangle, let’s help Nico and Nia find which foods to order for lunch. Look at the menu! Can you point to all of the foods that are triangle shaped? Here’s one! This slice of pizza! This slice of pizza has all of the properties of a triangle! Here is another one! A triangle is made by this half of a sandwich! There is one on this slice of cake! "And the last one is found from this slice of watermelon!" Remember, shapes must have certain properties to be able to be called that shape. A triangle is a closed shape that always has three sides and three corners or vertices.

But, a triangle can be any size or colour and face any direction. "Yum! This lunch is delicious!" "Yes! It's TRI-iffic!"