Plane shapes

Plane shapes are flat. You can draw them on paper. Let's meet the four most useful ones up close.

Circle

A circle is perfectly round. It has no corners and no straight sides — only one smooth, curved edge.

Examples: a coin, a wheel, the moon, a clock face.

Square

A square has four sides, and all four sides are exactly the same length. It also has four corners that are equally "square" — none of them is sharp or open.

Examples: a chocolate bar piece, a dice face, a paper napkin folded.

Triangle

A triangle has three sides and three corners. The sides do not have to be the same length — there are tall, skinny triangles and wide, short ones.

Examples: a slice of pizza, a roof, a road sign.

Rectangle

A rectangle has four sides and four corners. Two of its sides are longer; the other two are shorter. A rectangle is like a stretched square.

Examples: a door, a book, a phone screen, a chocolate bar.

Counting corners

Counting corners is a fun game and a great clue:

• Circle → 0 corners
• Triangle → 3 corners
• Square / rectangle → 4 corners

If you see 3 corners, it is a triangle. Always.

A square is also a rectangle

Surprise! A square is a special kind of rectangle — one whose long and short sides happen to be the same length. That trick is for older grades, but you can already remember: every square fits the rectangle rules.

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