Go Math! Grade 3, Chapter 10: Two-Dimensional Shapes
In this unit, your child describes plane shapes, flat shapes, by their sides and angles. They learn names like polygon, quadrilateral, and rhombus, sort shapes into groups that share attributes, and draw quadrilaterals that fit a rule. They also split shapes into equal areas and name each part as a fraction. Perimeter and area come next.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Chapter 10?
- Classifying quadrilaterals by their sides and angles, and using a Venn diagram to show which shapes fit more than one group. Learn more: Sorting four-sided shapes into families
- Partitioning shapes into equal areas, so a hexagon split into 6 matching triangles shows sixths. Learn more: Splitting shapes into equal parts
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
Look at the shapes. They are all quadrilaterals. How many of them have 4 square corners?
- 2
- 3
- 1
How you can help
- Ask your child to describe a window, a sign, or a book cover by its sides and corners, then name the shape group it belongs to.
- Make shapes with straws or pipe cleaners and ask your child to build a quadrilateral that is not a rectangle.
- Fold a square napkin corner to corner into 4 equal triangles and ask whether each triangle is still 1/4 of the napkin.
Where kids can get stuck
- Saying a square cannot be a rectangle because it already has its own name.
- Counting a shape with a curved side as a polygon, though polygons have only straight sides.
- Thinking two halves must match in shape to be equal, even when they cover the same area.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- polygon
- A closed flat shape with straight sides.
- quadrilateral
- A flat shape with exactly 4 straight sides and 4 corners.
- angle
- The corner made where two sides of a shape meet.
- right angle
- A square corner, like the corner of a sheet of paper.
- rhombus
- A four-sided shape with all sides equal, like a pushed-over square.
- attribute
- Something about a shape you can check, like how many sides it has.
- Venn diagram
- Overlapping circles used to sort things, with shared things in the middle.
- equal area
- Parts that cover the same amount of space, even if they look different.
Ready to build your child’s confidence with flat shapes?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
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Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does Go Math! Grade 3 Chapter 10 cover?
Go Math! Grade 3 Chapter 10 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.