Flat shapes are made from sides and corners that we can see and count. A side is a straight edge of a shape, and a corner is a point where two sides meet. Learning to count sides and corners helps young learners describe shapes clearly.
A triangle is a great first shape because it always has 3 sides and 3 corners.
Key Facts
- A side is one straight edge of a flat shape.
- A corner is where two sides meet.
- Triangle sides = 3.
- Triangle corners = 3.
- Trace each side with your finger to help count without skipping.
- Count each corner one time by touching the point and saying the number.
Vocabulary
- Shape
- A shape is a flat figure with an outside edge.
- Side
- A side is a straight line that forms part of a shape.
- Corner
- A corner is a point where two sides come together.
- Triangle
- A triangle is a flat shape with 3 sides and 3 corners.
- Trace
- To trace means to follow the edge of a shape with your finger or pencil.
Common Mistakes to Avoid
- Counting the same side twice is wrong because each side should be counted only one time.
- Skipping a corner is wrong because every point where two sides meet is part of the shape.
- Calling a curved edge a side is wrong for this lesson because sides are straight edges on flat shapes.
- Starting to count without a plan is wrong because it can make you lose your place, so touch and trace each side in order.
Practice Questions
- 1 A triangle has 3 sides. If you touch and count 1 side, then 2 sides, then 3 sides, how many sides did you count in all?
- 2 Draw 2 triangles. How many corners are there altogether?
- 3 A child traces around a triangle with a finger. Explain how tracing helps the child count the sides and corners correctly.