# Understanding 2D Shapes and Their Attributes

Understanding and identifying basic 2D shapes based on their attributes is a first grade, Common Core math skill: 1.GA.1.  Below we show two videos that demonstrate this standard. Then, we provide a breakdown of the specific steps in the videos to help you teach your class.

Prior Learnings

Your students should be familiar with the Kindergarten skill of naming regular shapes (i.e. squares, circles, triangles, etc.) and using formal and informal language to analyze and compare the shapes (K.G.1-3). They should also be familiar with making simple shapes to form larger shapes (K.G.6).

Future Learnings

This 1st grade skill of understanding halves and fourths will help your students when they move onto 2nd grade. By understanding halves and fourths, your students will be able to work with, draw, and analyze shapes. Your students will learn to identify more complex shapes: triangles, quadrilaterals, hexagons and cubes (2.G.1).

They will also be able to cut shapes into equal parts and deepen their understanding of “part and whole relationship,” explaining that a whole can be made up of parts (i.e. three thirds, four fourths, etc..) They will also learn that the “equal shares of identical wholes” do not need to the same shape to equal each other (2.G.2-3).

Common Core Standard: 1.GA.1 - Distinguish between defining attributes versus non-defining attributes

Students who understand this principle can:

1. Understand and explain the difference between defining and non-defining attributes (i.e. number of sides/corners vs. color and size)
2. Identify basic 2D shapes: rectangles, squares, trapezoids, triangles, etc.
3. Identify basic 3D shapes: cubes, right circular cones, right circular cylinders, etc.
4. Create a shape when given a list of defining attributes.

Video 1: Understanding Basic Shapes and Attributes

The video begins by listing some attributes of common shapes.

1. Shapes can have multiple sides: some straight, some curved.
a. It shows two shapes with straight and curved sides, identifying both.
2. Shapes have corners which are also called angles or vertices.
a. An angle is where two sides meet to close a shape.
3. Some shapes are closed and some are open.
a. Provides examples of open and closed shapes.

The video then reviews some common shapes, discussing their attributes.

1. A triangle is the first shape.
a. It is closed.
b. It has 3 straight sides and 3 corners.
2. A square is a second shape.
a. It is closed.
b. It has 4 straight sides and 4 corners.
c. A square has sides and corners that are all the same size.
3. A rectangle is the third shape.
a. It is closed.
b. It has 4 straight sides and 4 corners.
c. It has opposite sides that are the same length. All corners are the same size.
4. A circle is the fourth shape.
a. It is closed.
b. It has zero straight sides and zero corners.
c. Instead, it is a curved, closed shape.

After, the video provides practice for students to match attributes of shapes. Your students can identify which shapes from the choices have the same attributes as the selected shape.

Video 2: Identifying Shapes Based on Their Attributes

The video begins by explaining that almost everything we see is made up of shapes. It then defines that a two-dimensional shape is a flat plane figure or a shape that has two dimensions: length and width.

To classify 2D shapes, Boddle explains we look at the number side and corners. The video then presents examples of basic shapes and reviews the attributes that classify them as such.

1. The first shape is a circle.
a. It has no side and no corners.
b. Coins and round clocks are examples of circles.
2. The second shape is an oval.
a. It is longer, more stretched than a circle.
b. It has no sides and no corners.
c. Footballs and watermelons are examples of ovals.
3. The third shape is a triangle.
a. It has 3 sides and 3 corners (vertices).
i. Vertices are where two sides meet.
i. A single corner is called a vertex.
b. Pizza slices and recycling symbols are examples of triangles.
4. The fourth shape is a square (quadrilateral).
a. It has 4 sides and 4 corners.
b. All 4 sides are equal.
c. Windows and pieces of chocolate are examples of squares.
5. The fifth shape is a rectangle (quadrilateral).
a. It has 4 sides and 4 corners.
b. It is like a stretched out square.
c. Its opposite sides are equal.
d. Notebooks and computer monitors are examples of rectangles.
6. A quadrilateral is any shape with 4 sides and 4 corners/vertices.

The video then offers additional practice for your students to understand and identify shapes.

Want more practice?