Year 2: 2-D shapes on the faces of 3-D shapes
Part of the Year 2 2-d and 3-d shapes chapter. Chapter overview · whole chapter on one page
2-D shapes on the faces of 3-D shapes
Solid shapes have faces. Each flat face is a 2-D shape.
A cube has 6 square faces. A cuboid has rectangle faces.
A cylinder has 2 flat ends. Each end is a circle.
A pyramid with a triangle base has triangle faces.
A sphere has no flat faces, so no 2-D shape is on it.
Key ideas
- A cube has 6 square faces.
- A cuboid has rectangle faces.
- A cylinder has 2 circle ends.
- A pyramid has triangle faces.
- A sphere has no flat faces.
Method. Look at one flat face of the cube. Then name its shape.
- Look at one flat face. A cube has flat faces that are squares.one flat face of the cube
- Check its sides. Count the straight sides, or check if the face is round.4 equal straight sides
- Name the shape. This flat face is a square.square
Check. Every flat face of this cube is the same kind of shape. ✓
Watch out. A face is flat, so it is a 2-D shape. The solid itself is 3-D.
Method. Look at one flat face of the cylinder. Then name its shape.
- Look at one flat face. A cylinder has flat faces that are circles.one flat face of the cylinder
- Check its sides. Count the straight sides, or check if the face is round.round, with no straight sides
- Name the shape. This flat face is a circle.circle
Check. Every flat face of this cylinder is the same kind of shape. ✓
Watch out. A face is flat, so it is a 2-D shape. The solid itself is 3-D.
Method. Look at one flat face of the pyramid. Then name its shape.
- Look at one flat face. A pyramid has flat faces that are triangles.one flat face of the pyramid
- Check its sides. Count the straight sides, or check if the face is round.3 straight sides
- Name the shape. This flat face is a triangle.triangle
Check. Every flat face of this pyramid is the same kind of shape. ✓
Watch out. A face is flat, so it is a 2-D shape. The solid itself is 3-D.
Watch out
Watch out: a face of a cube is a square, not a cube. A cube is 3-D. A square is 2-D. The curved side of a cylinder is not a flat 2-D shape.
Exam tip
Grown-up tip. Find a box, a tin and a ball at home. Ask: “What shape is the flat side?” Then ask: “Does the ball have a flat side?”
Exercise 8D 2-D shapes on the faces of 3-D shapes
Non-calculatorMethod. Look at one flat face of the cube. Then name its shape.
- Look at one flat face. A cube has flat faces that are squares.one flat face of the cube
- Check its sides. Count the straight sides, or check if the face is round.4 equal straight sides
- Name the shape. This flat face is a square.square
Check. Every flat face of this cube is the same kind of shape. ✓
Watch out. A face is flat, so it is a 2-D shape. The solid itself is 3-D.
Method. Look at one flat face of the cuboid. Then name its shape.
- Look at one flat face. A cuboid has flat faces that are rectangles.one flat face of the cuboid
- Check its sides. Count the straight sides, or check if the face is round.4 straight sides, two long and two short
- Name the shape. This flat face is a rectangle.rectangle
Check. Every flat face of this cuboid is the same kind of shape. ✓
Watch out. A face is flat, so it is a 2-D shape. The solid itself is 3-D.
Method. Look at one flat face of the cylinder. Then name its shape.
- Look at one flat face. A cylinder has flat faces that are circles.one flat face of the cylinder
- Check its sides. Count the straight sides, or check if the face is round.round, with no straight sides
- Name the shape. This flat face is a circle.circle
Check. Every flat face of this cylinder is the same kind of shape. ✓
Watch out. A face is flat, so it is a 2-D shape. The solid itself is 3-D.
Method. Look at one flat face of the pyramid. Then name its shape.
- Look at one flat face. A pyramid has flat faces that are triangles.one flat face of the pyramid
- Check its sides. Count the straight sides, or check if the face is round.3 straight sides
- Name the shape. This flat face is a triangle.triangle
Check. Every flat face of this pyramid is the same kind of shape. ✓
Watch out. A face is flat, so it is a 2-D shape. The solid itself is 3-D.
Method. Look at one flat face of the cone. Then name its shape.
- Look at one flat face. A cone has flat faces that are circles.one flat face of the cone
- Check its sides. Count the straight sides, or check if the face is round.round, with no straight sides
- Name the shape. This flat face is a circle.circle
Check. Every flat face of this cone is the same kind of shape. ✓
Watch out. A face is flat, so it is a 2-D shape. The solid itself is 3-D.
Method. Check the shape of a face of each shape. Then pick the one that matches.
- Look at each shape. Check the shape of a face of each one.A: triangle; B: square; C: circle
- Find the one that matches. A cube has square faces, so B is the answer.B matches
- Write the answer. B
Check. Check each of the other shapes too. Only B matches. ✓
Watch out. Check every shape, not only the first one you see.
Method. Check the shape of a face of each shape. Then pick the one that matches.
- Look at each shape. Check the shape of a face of each one.A: circle; B: rectangle; C: triangle
- Find the one that matches. A cuboid has rectangle faces, so B is the answer.B matches
- Write the answer. B
Check. Check each of the other shapes too. Only B matches. ✓
Watch out. Check every shape, not only the first one you see.
Method. Check the shape of the flat end of each shape. Then pick the one that matches.
- Look at each shape. Check the shape of the flat end of each one.A: triangle; B: square; C: circle
- Find the one that matches. A cylinder has circle ends, so C is the answer.C matches
- Write the answer. C
Check. Check each of the other shapes too. Only C matches. ✓
Watch out. Check every shape, not only the first one you see.
Method. Look at one flat face of the cylinder. Then name its shape.
- Look at one flat face. A cylinder has flat faces that are circles.one flat face of the cylinder
- Check its sides. Count the straight sides, or check if the face is round.round, with no straight sides
- Name the shape. This flat face is a circle.circle
Check. Every flat face of this cylinder is the same kind of shape. ✓
Watch out. A face is flat, so it is a 2-D shape. The solid itself is 3-D.
Method. Look at one flat face of the cube. Then name its shape.
- Look at one flat face. A cube has flat faces that are squares.one flat face of the cube
- Check its sides. Count the straight sides, or check if the face is round.4 equal straight sides
- Name the shape. This flat face is a square.square
Check. Every flat face of this cube is the same kind of shape. ✓
Watch out. A face is flat, so it is a 2-D shape. The solid itself is 3-D.
Method. Look at one flat face of the cuboid. Then name its shape.
- Look at one flat face. A cuboid has flat faces that are rectangles.one flat face of the cuboid
- Check its sides. Count the straight sides, or check if the face is round.4 straight sides, two long and two short
- Name the shape. This flat face is a rectangle.rectangle
Check. Every flat face of this cuboid is the same kind of shape. ✓
Watch out. A face is flat, so it is a 2-D shape. The solid itself is 3-D.
Method. Look at the surface of the sphere.
- Look for a flat part. The whole surface of a sphere is curved.curved all over
- Decide. A sphere has no flat faces.flat faces: 0
- Write the answer. No
Check. A sphere has 0 flat faces. ✓
Watch out. A ball rolls because it has no flat faces.
Method. Check the shape of the faces of each shape. Then pick the one that matches.
- Look at each shape. Check the shape of the faces of each one.A: cube has square faces; B: pyramid has triangle faces; C: cuboid has rectangle faces
- Find the one that matches. Only the pyramid has triangle faces.pyramid matches
- Write the answer. pyramid
Check. Check each of the other shapes too. Only pyramid matches. ✓
Watch out. Check every shape, not only the first one you see.
Method. Look at the faces of the cube.
- Look at one face. Each face of a cube is a square.square
- Check the others. All 6 faces of a cube are squares.6 squares
- Decide. Ben is not right.No
Check. A square has 4 sides, not 3, so it is not a triangle. ✓
Watch out. A triangle has 3 sides. A square has 4.
Method. Check the number of flat circle faces of each shape. Then pick the one that matches.
- Look at each shape. Check the number of flat circle faces of each one.A: cone has 1 flat circle base; B: cylinder has 2 flat circle ends
- Find the one that matches. Only the cylinder has 2 flat circle ends.cylinder matches
- Write the answer. cylinder
Check. Check each of the other shapes too. Only cylinder matches. ✓
Watch out. Check every shape, not only the first one you see.
Method. Think about the faces of a box.
- Look at the faces. All 6 faces are the same square.6 square faces
- Think about the edges. When all faces are squares, all the edges are the same length.all edges equal
- Decide. That shape is a cube, so the answer is Yes.Yes
Check. A cube has 6 square faces and 12 edges that are all the same length. ✓
Watch out. A cuboid has rectangle faces, so it is not always square.