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โญ• Circle, Triangle, Rectangle Sort

Flat shapes split into
curved shapes and polygons

Flat shapes fall into two big groups โ€” polygons (triangles, rectangles, and more) surrounded by straight sides, and circles, which curve smoothly around with no sides or corners at all. First explore the structure of a circle, then try a quiz mixing circles and polygons together and naming each one.

Flat shapes split into two big groups. Shapes surrounded by straight line segments (sides), like triangles and rectangles, are called polygons, and their name changes based on the number of sides (3 sides = triangle, 4 sides = quadrilateral...). A circle is completely different from these polygons โ€” it has no sides and no corners at all, just a smooth curve made of every point that's the same distance from one center point.

The surest way to tell shapes apart is to count the sides. No sides at all means a circle; if there are sides, the number of them decides whether it's a triangle, a quadrilateral, a pentagon, and so on. Know this one rule, and you can name any shape, no matter how oddly it's drawn.

First explore how a circle is drawn using the radius slider, then in the quiz, look at different shapes, count their sides, and try naming them.

โ‘  Circle โ€” a shape with no sides or corners
Radius 70
Diameter = radius ร— 2
140
The radius is the distance from the circle's center to its edge; the diameter is the distance straight across, connecting two opposite ends.

๐Ÿงฉ โ‘ก Name that shape โ€” circle or polygon?

Question 1/10 ยท Correct 0
Sides with the same number of tick marks are the same length (1 mark matches 1 mark, 2 marks match 2 marks)
A small square mark (โŒ) at a corner means that angle is a right angle (90ยฐ)