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Shapes, Symmetry & Nets

Maths · Year 3 NAPLAN
Year 3
Lesson Guide
Explanation
A cylinder has two flat circle ends and a curved side, like a tin of beans. A cone has one circle end and comes up to a point, like a party hat. A sphere is a ball with no flat faces at all. A cube has six square faces, all the same size. The quickest way to tell a cone from a cylinder is to ask whether it comes to a point — a cone does and a cylinder does not.
Your Turn
Is a can of drink a cylinder or a cone? Check: a cylinder — two circle ends, no point.
Watch Out
A cylinder and a cone both have a circle, so check for the point before you choose.
Explanation
Some questions ask what an object looks like from directly above. Imagine a bird flying over it — what outline does it see? A cone from above is a circle with the point in the middle. A cylinder from above is a circle too. A cube from above is a square, and a square pyramid from above is a square with lines going to the middle. Remember that a view from above never shows the height, so a tall cone and a short one look exactly the same from up there.
Your Turn
What does a cylinder look like from above? Check: a circle.
Watch Out
From above you see the outline, not the side. A cone is not a triangle from above.
Explanation
A net is an object flattened out so you can see all its faces. A cube net always has exactly six squares, so count them first — if there are not six, cross that option out straight away. Then check that no two squares would land on top of each other when it folds. The shape on the right has six squares but folding it puts two faces in the same place, so it fails. One net always works and is worth remembering: a row of four squares with one square above the row and one below it.
Your Turn
How many squares must a cube net have? Check: exactly 6 — one for each face.
Watch Out
Six squares is not enough on its own. Two of them can still overlap when it folds.
Explanation
A face is a flat surface, an edge is a line where two faces meet, and a corner is a point where edges meet. Take a pyramid made from one square and four triangles. It has five faces, because that is one square plus four triangles. For the edges, count in two groups: four round the square base, plus four going up to the point, which makes eight. Counting in groups like that stops you losing your place. It has five corners — four at the base and one at the top. And a cube has six faces, twelve edges and eight corners.
Your Turn
How many edges does a cube have? Check: 4 on top, 4 on the bottom, 4 up the sides — 12.
Watch Out
Faces, edges and corners are three different counts. Read which one the question wants.
Explanation
A fold line works like a mirror, so whatever you cut out appears on both sides when you unfold the paper, and the hole is always symmetrical about the fold. That is how the fold-and-cut questions work. Turns are the other idea here: a quarter turn is a right angle, and four quarter turns bring a shape all the way back to where it started. Clockwise means the way clock hands go — up, then right, then down, then left. That is the whole lesson: naming objects, looking from above, nets, faces and edges, and symmetry and turns. Quiz and exercises now.
Your Turn
A shape is turned a quarter turn clockwise four times. Where is it? Check: back at the start.
Watch Out
Fold-and-cut answers are always symmetrical. Cross out any option that is not.
📌 Key Points — this lesson in a nutshell
  • A cylinder has two circle ends; a cone has one circle end and a point.
  • From above, a cone and a cylinder both look like a circle.
  • A net is a shape flattened out. A cube net has exactly 6 squares.
  • Counting cubes in a stack: do not forget the ones hidden behind.
Step 1: Introduction
Step 1 of 5
Which one is a cylinder? A B C D B is the cylinder: two flat circle ends with a curved side, like a tin. A is a cone — one circle end and a point, like a party hat. C is a sphere — a ball, no flat faces at all. D is a cube — six square faces, all the same size. The quickest way to tell a cone from a cylinder: does it come to a point?
What you see from directly above a cone from the side → from above: a circle Looking straight down on a cone, you see a circle with the point in the middle. A cylinder from above is a circle too. A cube from above is a square. A square pyramid from above is a square with lines to the middle. Imagine a bird flying over the object. What outline would it see? A view from above never shows the height, so a tall cone and a short one look the same.
Which net folds into a cube? folds into a cube ✓ does not ✗ A net is the object flattened out. A cube net always has exactly 6 squares. First count the squares. If there are not 6, cross it out straight away. Then check no two squares would land on top of each other when it folds. The one on the right has 6 squares, but folding it puts two faces in the same place. A row of 4 with one square above and one below always works. That is worth remembering.
A pyramid made from 1 square and 4 triangles faces — the flat surfaces5 edges — where two faces meet8 corners — where edges meet5 4 edges round the square base, plus 4 going up to the point: 8 edges. Count in two groups like that and you will not lose your place. A cube has 6 faces, 12 edges and 8 corners. A face is flat, an edge is a line, a corner is a point. Read which one is wanted.
Fold, cut, and turn one line of symmetry folded, then cut unfolded: the hole is doubled A fold line is a mirror. Whatever you cut appears on BOTH sides when you unfold. So the hole in the unfolded paper is always symmetrical about the fold. A quarter turn is a right angle. Four quarter turns bring a shape all the way back. Clockwise is the way clock hands go: up, right, down, left. Naming · from above · nets · faces and edges · symmetry and turns. Quiz and exercises now.
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