Understand 3D shapes and their nets using gift box scenarios!
Scenario: You're wrapping a gift for your friend's birthday. The gift is a rectangular box that's 10cm long, 8cm wide, and 6cm tall. To wrap it properly, you need to understand the 3D shape and how it unfolds into a flat pattern (net). Can you help identify the faces, edges, and vertices?
3D (three-dimensional) shapes are solid shapes that have length, width, and height (depth). Unlike 2D shapes, you can hold 3D shapes in your hands. They take up space in three directions.
Cube
Rectangular Prism
Sphere
Cylinder
Every 3D shape has faces, edges, and vertices
Boxes, balls, cans, buildings, and many everyday objects
Every 3D shape has three main parts that help us describe and understand it:
Faces: The flat surfaces of the shape
Like the sides of a box
Edges: The lines where two faces meet
Like the corners of a box
Vertices: The points where edges meet
Like the corner points of a box
Let's count the faces, edges, and vertices of our rectangular gift box:
Faces: 6 (top, bottom, front, back, left, right)
All rectangular faces
Edges: 12 (4 around top, 4 around bottom, 4 vertical)
Where faces meet
Vertices: 8 (4 on top, 4 on bottom)
Corner points
A net is a 2D pattern that can be folded to make a 3D shape. It's like taking a 3D shape and "unfolding" it flat on a table. When you fold the net back up, you get the original 3D shape.
Net → Fold → 3D Shape
2D pattern becomes 3D object
Like a blueprint or template for making a 3D shape
Gift boxes, cereal boxes, shipping containers
Our gift box is a rectangular prism. Here's what its net looks like:
Net of a rectangular prism (gift box)
When you fold this net along the edges, it becomes our 3D gift box!
A cube is a special rectangular prism where all faces are squares. How many faces, edges, and vertices does a cube have?
Faces: 6 (all square faces)
Top, bottom, front, back, left, right
Edges: 12 (4 around each face)
Where square faces meet
Vertices: 8 (4 on top, 4 on bottom)
Corner points
Which of these nets can be folded to make a cube?
Net A: 6 squares in a cross pattern
✓ Can make a cube
Cross pattern works
Net B: 5 squares in a line
✗ Cannot make a cube
Need 6 squares