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Grade 1 (age 6-7)

2D Shapes

2D Shapes

Flat shapes are the thin shapes you can draw on paper: round circles, pointy triangles, and neat squares. A circle has no sides or corners, but a triangle has 3 and a square has 4. Each straight line is a side, and each point where two sides meet is a vertex. Switch shapes and add sides here to count them yourself.

What is 2D?
📄 2D = Flat Shapes
①Shapes you can draw on paper
②No thickness, flat
③Learn ○ △ □!
Let's Look at Shapes
0 Circle
🔍 Circle
①A circle is round and smooth
②No sides, no vertices
③Coins, clocks, wheels are circles
④Rolls in any direction
Counting Sides and Vertices
3
✏️ Sides and Vertices
①A straight line is a "side"
②Where sides meet is a "vertex"
③Triangle: 3 sides, 3 vertices
④Square: 4 sides, 4 vertices
⑤Number of sides = number of vertices!
Summary
Circle (○)
0 sides, 0 vertices
Round, no points
Triangle (△)
3 sides, 3 vertices
3 points, 3 straight lines
Square (□)
4 sides, 4 vertices
4 even points, 4 straight lines
🎯 Remember!
①○ Circle — 0 sides, 0 vertices
②△ Triangle — 3 sides, 3 vertices
③□ Square — 4 sides, 4 vertices
④Sides = vertices
⑤Find shapes around you!
Examples and Unit Test
Example 1
Which flat shape has 3 sides and 3 vertices?
1
Think of a shape with 3 straight sides.
2
A shape with 3 sides and 3 vertices is a triangle.
▸ Triangle
In a flat shape, the number of sides equals the number of vertices.
Example 2
Which round flat shape has no straight sides and no vertices?
1
Look for a shape with no sides and no vertices.
2
A round circle has 0 sides and 0 vertices.
▸ Circle
A circle has no straight sides, so it rolls in any direction.
Unit Test
Which flat shape has 4 sides?
①triangle
②square
③circle
④point
▸ ② square
1
Look for a shape with 4 sides and 4 vertices.
2
A triangle has 3 sides, a circle has 0, and a square has 4 sides.
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3D Shapes
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Clock Reading