Sort shapes into groups, like quadrilaterals
Learning to sort shapes by their features teaches your child to trust a definition over a first glance, so a square tilted onto its corner is still a square. That habit carries into 4th grade, where shapes are grouped by parallel lines and angles, and into 5th grade, where they are arranged into families. Later geometry, including showing that something is always true, builds on this same careful thinking.
In this video, your child will learn to sort shapes into groups, like quadrilaterals.
The lesson stops at each question for your child's answer.
Three problems, each a little harder
Each problem is worked step by step. Your child will solve the last one before Bobby shows how.
Example 1
What do we call any shape with four sides?
Example 2
What group are a rhombus and a square both in?
Your child's turn
A square has four equal sides and four square corners. Which group is it in: rhombuses, triangles or pentagons?
The three key steps
- 1Count the sides.
- 24 straight sides: quadrilateral
- 3Some: rhombus, rectangle, square
Mistakes to listen for
- Saying a square is not a rectangle because it does not look long and thin, though it has four square corners.
- Thinking a turned shape becomes a different shape, calling a tilted square a diamond instead of a square.
- Counting only rectangles and squares as quadrilaterals, leaving out shapes with four uneven straight sides.
The lesson shows every step, so your child sees why it works. Read our parent's guide to sorting four-sided shapes into families →
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More 3rd grade Geometry, with questions your child answers along the way.
Questions parents ask
Does my child need an account to watch?
No. You can watch this on any device at any time. If your child would like to practice sorting four-sided shapes into families, and you'd like parent-friendly reports on your child's progress and growth, you can join Bobby's Math Club for unlimited free practice.
What happens when my child answers a question?
A right answer gets a cheer, and the lesson carries on. If your child isn't sure, they can tap "I don't know yet", and Bobby gives the answer and shows another example. Nothing is scored or stored.
Is this the same lesson that's on YouTube?
Yes. Here, the lesson stops at each question and waits for your child to answer. On YouTube, each question stays on screen for a few seconds, and then the lesson plays on.
Where can I learn more?
There's a short, kid-friendly lesson like this one for every Pre-K to 5th grade math skill, all in our video library. Our parent's guide to sorting four-sided shapes into families has more on where kids get stuck and how you can help at home. In the club, your child practices at just the right level, about five minutes a day, and you get parent-friendly reports as they grow. Learn more about how it works →
Practice sorting four-sided shapes into families
Questions at your child's level, about five minutes a day, on sorting four-sided shapes into families and whatever PK-5 skills they need to develop. Unlimited practice, free forever.
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