Learn to Identify Two-Dimensional Shapes
🤓 Look at these objects.
Can you tell the shapes of these objects? 🤔
Very good! 😁
The first object is a triangle. The coin is a circle, and the chessboard is a square.
These are examples of two-dimensional shapes!
Let's review about them. 🤗
What is a Two-Dimensional Shape?
Look at this picture. 👇
Can you tell how the square is different from the cube? 🤔
The square is different from the cube in many ways:
✅ The square only has length and width. It has no depth.
✅ When placed on a surface, the square will lie flat on it.
✅ We can easily draw a square on paper.
2D Shapes are flat. They only have two measurements - length and width. This is why they are called two-dimensional, or 2D!
Some other examples of 2D shapes are circles, triangles and rectangles.
Sides, Vertices and Angles
😎 Most 2D shapes are made up of lines and corners. These parts of a shape have some special names.
- The line segments that make a 2D shape are called its sides.
- A corner at which two sides of a 2D shape meet is called a vertex. Two or more corners are called vertices (not vertexes!).
- A measure of the turn between the two sides that meet at a vertex is called the angle between the sides.
Let's now look at some 2D shapes. 🤓
A triangle is made up of 3 sides. These sides may or may not be equal.
It has 3 vertices and 3 angles.
A rectangle has 4 sides, 4 vertices and 4 right angles (90° angles).
Opposite sides of a rectangle are equal and parallel to each other.
🤓 Tip: The word quadrilateral means a 4 sided shape. Rectangles are quadrilaterals.
A square is a special type of rectangle, in which all 4 sides are equal.
Like a rectangle, a square also has 4 vertices, 4 right angles, and parallel opposite sides.
A rhombus looks like a diamond, or a lopsided square.
Like a square, a rhombus also has 4 equal sides and 4 vertices.
Opposite sides of a rhombus are parallel to each other.
Opposite angles of a rhombus are equal to each other.
Tip: A square is a rhombus. But not all rhombuses are squares!
A trapezoid also has 4 sides, 4 vertices and 4 angles.
A trapezoid is 4-sided shape with only 1 pair of parallel sides.
So squares and rectangles are not trapezoids.👍
A pentagon has 5 equal sides, 5 vertices and 5 equal angles.
A hexagon has 6 equal sides, 6 vertices and 6 equal angles.
An octagon has 8 equal sides, 8 vertices and 8 equal angles.
A circle is a round shape that has no sides or vertices.
The distance from the center of a circle to any point on its boundary always remains the same.
Watch and Learn
Great job learning about two-dimensional shapes! 👏
Now you can start your practice below. 💪