Lesson 7.4 · Shapes
Comparing and building shapes
How is a square like a rectangle? How is it different? You can compare shapes by counting. You can even snap small shapes together to make bigger ones!
Comparing shapes
To compare two shapes, count their sides and corners. Then look at how they are the same and how they are different.
| Triangle 🔺 | Square 🟦 | |
|---|---|---|
| Sides | 3 | 4 |
| Corners | 3 | 4 |
A square has 1 more side than a triangle.
Same and different
Count the sides and the corners. Shapes with the same number of sides can be alike. Shapes with a different number of sides are different kinds of shapes.
Building shapes
You can put small shapes together to make a new shape.
Two triangles can make a square. Draw a line from one corner of a square to the opposite corner. Now you see 2 triangles!
Two squares side by side make a rectangle: 🟦🟦
Worked example: Same or different?
How are a square and a rectangle the same?
Both have 4 sides and 4 corners. They can look different. All 4 sides of a square are the same length, but a rectangle can have 2 long sides and 2 short sides.
Worked example: How many more?
A hexagon has 6 sides. A triangle has 3 sides. How many more sides does the hexagon have?
Count up from 3 to 6: four, five, six. That is 3 more. The hexagon has 3 more sides.
Worked example: Build a shape
Put these two squares side by side: 🟦🟦
What new shape do they make? The new shape is long, with 4 sides and 4 corners. It is a rectangle.
Tip
To check a shape you built, trace around the outside only. Count those sides to name the new shape.
Practice
A triangle has 3 sides. A square has 4 sides. How many more sides does the square have?
Type a number.
Which two shapes have the same number of sides?
What shape do two squares make when you put them side by side? 🟦🟦
How many triangles do you need to make a square?
Type a number.
How is a circle different from a square?
Sam has 2 triangles. He counts the sides of each triangle. How many sides do the 2 triangles have in all?
🔺 🔺
Type a number.