Circles

“Nico, look at all those fun prizes in that machine! Do you think you can pick one up with the claw?” “Looks tricky, but let’s give it a try!” Nico pulled two prizes out of the claw machine. A play clock and a frisbee. “These two prizes are different, but the outside shape of them look the same!” “Yes, they are both round!” “Let’s make the claw machine even trickier by trying to get more prizes that have a round shape!” Circles. Shapes are two-dimensional figures that we can name based on their defining properties. Defining properties are characteristics that a shape must have. Let’s look at a circle. The defining properties of a circle are that it must be a closed shape that has a curved line that is round, no sides and no vertices. A circle also must be the same distance from the centre all the way around. If defining properties are characteristics a shape must have, what are non-defining properties? A non-defining property is something that a shape has, but doesn’t always have to be the same. Size is a non-defining property. A circle can be big, big, big! Or a circle can be small, small, small. Colour is another non-defining property. Circles can be any colour! Circles can also face many different directions. No matter how you turn it, a circle always looks the same! Let’s identify circles. Is this a circle? Start by looking at the shape. Is it a closed round shape made with a curved line? Yes, it is a closed round shape made with a curved line. Does it have sides? No, it doesn’t have any sides. Does it have any vertices? No, it doesn’t have any vertices. Is there an equal distance from the centre to the edge of the circle? Yes there is an equal distance from the centre to all parts of the outside of the circle. This is a circle. Let’s try this one. Is this a circle? Is it a closed round shape made with a curved line? Yes, it is a closed round shape made with a curved line. Does it have sides? No, it doesn’t have any sides. Does it have any vertices? No, it doesn’t have any vertices. Is there an equal distance around from the center? No, this shape is not an equal distance around from the centre. This shape is not a circle. Now that we know all the properties of a circle, let’s see if we can help Nico and Nia find more prizes that have a circular shape. Look at the claw machine. Can you point to the other prizes that have the outside shape of a circle? Here’s one! This stuffed cookie! This ring also makes the shape of a circle. And here's one more, this sparkling golden yoyo! Remember, shapes have defining and non-defining properties. A circle is a closed round shape that is made with a curved line. It doesn't have any sides or vertices but it must be equal distance all the way around the centre. A circle can be any size or colour and face in any direction. Nico and Nia see they have one token left. They can only go after one more prize! “I really hope we get the golden yoyo, Nico!" YAY! "YAY!"