Nets of Solids
Nets of the cube, cuboid, prism, pyramid, cylinder and cone, and matching a flat net to its solid.
⏱ 6 min · 🎯 4 things to master
Think about flattening a cereal box: cut along some edges, open it out, and it lies flat as a strange cross shape. That flat shape is a net — the solid unfolded. PSLE net questions ask you to picture the folding in your head, going from flat to solid and back. Once you know the faces each solid has, matching a net to its shape becomes a counting game.
Parents: ask your child to imagine the folding and predict the solid before they reveal. The "Method tip" boxes name the exact properties a PSLE marker checks for each net.
By the end you'll be able to say what a net is, recognise the nets of common solids, and match a net to the right solid. Let's unfold.
What a net is
A is what you get when you open a solid out flat along its edges. Every of the solid appears once in the net, and the right edges line up to fold back together.
So to check if a net works, count the faces and picture them folding. If folding would make two faces overlap, or leave a gap, the net is wrong. A correct net has exactly the right number of faces in positions that close up neatly.
🤔 Predict first: What is a net?
Nets of cubes and cuboids
A cube has 6 square faces, so its net is made of 6 squares joined edge to edge. There are several correct arrangements, but the classic one is a row of four squares with one square above and one below. A cuboid also has 6 faces, but they are rectangles, with opposite faces matching in size.
A quick test for a cube net: when you imagine folding, no two squares should land on top of each other. If they would overlap, that arrangement is not a valid net.
🤔 Predict first: How many faces does the net of a cube have?
Nets of prisms and pyramids
A has two identical end faces joined by rectangles. A triangular prism's net has 2 triangles (the ends) and 3 rectangles (the sides). A has one base and triangular faces that meet at a top point.
So a square-based pyramid's net has 1 square (the base) and 4 triangles that fold up to a single apex. Counting the base shape and the triangles tells you which solid a net makes.
🤔 Predict first: A net has 2 triangles and 3 rectangles. Which solid does it fold into?
Nets of cylinders and cones
A opens out into 2 circles (the top and bottom) and 1 rectangle that curls round to form the side. Picture peeling the label off a tin — it lies flat as a rectangle.
A has 1 circle (the base) and 1 curved sector that wraps up to a point. Counting the circles is the fastest way to tell a cylinder net from a cone net.
🤔 Predict first: A net has 2 circles and 1 rectangle. Which solid does it make?
Watch out — these are easily mixed up
Quick recap
🎯 Mastery check
Answer all 6 — your progress is saved on this device.
How many faces does the net of a cube have?
A net has 1 square and 4 triangles. Which solid does it fold into?
A net has 2 circles and 1 rectangle. Which solid is it?
A net has 2 triangles and 3 rectangles. Which solid is it?
How many circles are in the net of a cone?
A net is made of 6 rectangles with opposite faces equal. Which solid does it fold into?