Lesson 97: Naming 2D shapes

🧮 MATH (40 Lessons) • 🟣 C. Geometry and Measurement

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Objective

I can name and describe 2D shapes like circles, triangles, squares, and rectangles. I can use words like sides and corners and find these shapes in real-life objects.

Materials

Mini-lesson — What are 2D shapes?

A 2D shape is a flat shape you can draw on paper. We can talk about how many sides and corners it has.

Circle

  • A circle is round.
  • It does not have straight sides or corners.
  • Examples: a coin, a clock face, a round button.

Triangle

  • A triangle has 3 straight sides.
  • It has 3 corners.
  • Examples: a road sign, a slice of pizza (triangle shaped).

Square

  • A square has 4 straight sides.
  • All the sides are the same length.
  • It has 4 corners.
  • Examples: a small tile, some windows, a game board square.

Rectangle

  • A rectangle also has 4 straight sides.
  • It has 2 longer sides and 2 shorter sides.
  • It has 4 corners.
  • Examples: a door, a book, a phone screen.

In this lesson, we will look at these 2D shapes, say their names, and talk about their sides, corners, and real-life examples.

Picture strip: Shape posters for 2D shapes

Circle & triangle

Square & rectangle

Guided Practice — Name and describe 2D shapes

You will look at shape cards or real objects, say the shape name, and talk about sides, corners, and real-life examples. Then you will use the tracing pad.

  1. Show a circle: Look at a circle card or a round object (like a coin). Say, "This is a circle. It is round and has no corners".
  2. Show a triangle: Point to each side and count 3 sides and 3 corners. Say, "This is a triangle".
  3. Show a square: Count the 4 sides. Check that they are all equal. Say, "This is a square".
  4. Show a rectangle: Count the 4 sides. Talk about 2 long sides and 2 short sides. Say, "This is a rectangle".
  5. Sort real objects: Hold up a book, a door, a clock, or a sign. Ask, "Which shape is this most like?" (circle, triangle, square, or rectangle).
  6. Talk about sides and corners: For each shape, ask: "How many sides? How many corners?" Say the numbers out loud together.
  7. Use the tracing pad: Trace shape words like circle, square, triangle, rectangle, or words like side and corner. Then write one short sentence, such as "A square has 4 sides."
Tracing Pad
Tracing snapshot for print
Tip: After you trace your words, draw one or two shapes and label them, such as "triangle" or "square". Add the number of sides under each shape.

Practice 1 — Name the 2D shape

[PLACEHOLDER PRACTICE 1]

Practice 2 — Sides and corners

[PLACEHOLDER PRACTICE 2]

Practice 3 — Find shapes in real life

[PLACEHOLDER PRACTICE 3]

Quick Check — Naming 2D shapes

Answer each question about 2D shapes. You may look at real objects around you to help.

1) What is a 2D shape?

2D shapes are flat shapes we can draw on paper.

2) Which shape is round and has no corners?

A circle is round and does not have corners.

3) How many sides does a triangle have?

A triangle has 3 sides and 3 corners.

4) Which shape has 4 sides that are all the same length?

In a square, all 4 sides are the same length.

5) A rectangle has:

A rectangle has 4 sides. Two are longer and two are shorter.

6) How many corners does a square have?

A square has 4 sides and 4 corners.

7) Which shape has no straight sides?

A circle is curved all the way around and has no straight sides.

8) A road warning sign that looks like a slice of pizza is often which shape?

Many warning signs use a triangle shape.

9) Which object is most like a rectangle?

Doors are usually rectangles.

10) Which object is most like a circle?

Many clocks have a round, circle face.

11) How many sides does a square have?

A square has 4 straight sides.

12) You see a window that looks like a square. Which sentence is true?

A square has 4 equal sides and 4 corners.

13) You draw a shape with 3 sides and 3 corners. What shape is it?

A triangle always has 3 sides and 3 corners.

14) Which picture could be a rectangle?

Rectangles have 4 sides, with 2 long and 2 short sides.

15) Why is it helpful to learn the names of 2D shapes?

Knowing shape names helps you describe and talk about the world around you.

Assessment (parent/teacher)

Exit ticket (student)

Next time I will practise…

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