2D Shapes
Learn
What are 2D Shapes?
2D shapes are flat shapes that have length and width but no thickness. "2D" means two-dimensional. You can draw them on paper!
Parts of a Shape
Shapes have special parts we can count:
Shape Words
- Side - A straight line that makes part of a shape
- Corner (Vertex) - The point where two sides meet
Meet the 2D Shapes!
Circle
A circle is round with no corners and no straight sides. It is perfectly round like a ball, a clock, or a cookie!
- Sides: 0 (it's curved!)
- Corners: 0
Triangle
A triangle has 3 sides and 3 corners. Think of a pizza slice or a yield sign!
- Sides: 3
- Corners: 3
Square
A square has 4 equal sides and 4 corners. All sides are the same length! Think of a cracker or a window.
- Sides: 4 (all the same length)
- Corners: 4
Rectangle
A rectangle has 4 sides and 4 corners. Two sides are long and two sides are short. Think of a door or a book!
- Sides: 4 (2 long, 2 short)
- Corners: 4
Hexagon
A hexagon has 6 sides and 6 corners. Think of a honeycomb!
- Sides: 6
- Corners: 6
Examples
Let's identify and describe shapes!
Example 1: A shape has 3 sides and 3 corners. What is it?
Step 1: Count the sides: 3
Step 2: Count the corners: 3
Answer: It is a triangle!
Example 2: A clock face is round with no corners. What shape is it?
Step 1: Is it round? Yes!
Step 2: Does it have corners? No!
Answer: It is a circle!
Example 3: A door has 4 corners and 4 sides. Two sides are longer. What shape is it?
Step 1: Count corners: 4
Step 2: Count sides: 4
Step 3: Are all sides equal? No, two are longer.
Answer: It is a rectangle!
Example 4: A cracker has 4 sides that are all the same length. What shape is it?
Step 1: Count sides: 4
Step 2: Are all sides equal? Yes!
Answer: It is a square!
Example 5: How are a square and rectangle alike? How are they different?
Alike: Both have 4 sides and 4 corners.
Different: A square has all equal sides. A rectangle has 2 long sides and 2 short sides.
Practice Problems
Identify these shapes!
1. I have 4 equal sides and 4 corners. What shape am I?
Show Answer
You are a square!
2. I am round with no sides or corners. What shape am I?
Show Answer
You are a circle!
3. I have 3 sides and 3 corners. What shape am I?
Show Answer
You are a triangle!
4. How many corners does a rectangle have?
Show Answer
A rectangle has 4 corners.
5. What shape is a stop sign? (Hint: it has 8 sides!)
Show Answer
A stop sign is an octagon - a shape with 8 sides!
6. How many sides does a hexagon have?
Show Answer
A hexagon has 6 sides.
7. Name something in your home that is shaped like a rectangle.
Show Answer
Possible answers: a door, book, TV, phone, window, table, and many more!
8. A pizza is usually what shape?
Show Answer
A pizza is usually a circle!
9. What is the difference between a side and a corner?
Show Answer
A side is a straight line. A corner is where two sides meet.
10. If you cut a square in half from corner to corner, what two shapes do you get?
Show Answer
You get two triangles!
Check Your Understanding
Answer these questions about 2D shapes!
1. What makes a shape "2D"?
Show Answer
A 2D shape is flat - it has length and width but no thickness. You can draw it on paper.
2. Which shapes have 4 corners? (Name two!)
Show Answer
Squares and rectangles both have 4 corners.
3. What is special about a circle compared to other shapes?
Show Answer
A circle has no sides and no corners. It is perfectly round!
4. Look around you! Find and name one shape you can see right now.
Show Answer
Answers will vary! You might see a rectangle (book, door), circle (clock, plate), square (window, tile), or triangle (roof, sign).
Next Steps
- Go on a shape hunt around your home or school
- Draw your own shapes and count their sides and corners
- When you are ready, move on to 3D Shapes
- You are a shape expert!