Year 2: Faces, edges and vertices of 3-D shapes
Part of the Year 2 2-d and 3-d shapes chapter. Chapter overview · whole chapter on one page
Faces, edges and vertices of 3-D shapes
A 3-D shape is solid. It has length, width and depth.
A face is a flat surface. An edge is a straight line where two faces meet.
A vertex is a corner. More than one vertex is vertices.
A cube has 6 faces, 12 edges and 8 vertices.
A sphere has no flat faces, no edges and no vertices.
Key ideas
- A face is a flat surface.
- An edge is a straight line where two faces meet.
- A vertex is a corner.
- A cube has 6 faces, 12 edges and 8 vertices.
Method. Count the flat faces of the cube. Count the ones you cannot see, like the bottom.
- Look at the shape. A face is a flat surface.a cube
- Count the flat faces. There are 6 flat faces on a cube.6 flat faces
- Write the answer. 6
Check. Faces plus vertices equals edges plus 2: 6 + 8 = 12 + 2. ✓
Watch out. Turn the shape in your mind. Hidden faces, like the base, still count.
Method. Count the vertices (corners) of the cuboid. Count the ones you cannot see, like the bottom.
- Look at the shape. A vertex is a sharp corner point.a cuboid
- Count the vertices (corners). There are 8 vertices (corners) on a cuboid.8 vertices (corners)
- Write the answer. 8
Check. Faces plus vertices equals edges plus 2: 6 + 8 = 12 + 2. ✓
Watch out. Turn the shape in your mind. Hidden faces, like the base, still count.
Method. Count the edges of the pyramid. Count the ones you cannot see, like the bottom.
- Look at the shape. An edge is a straight line where two faces meet.a pyramid
- Count the edges. There are 6 edges on a pyramid.6 edges
- Write the answer. 6
Check. Faces plus vertices equals edges plus 2: 4 + 4 = 6 + 2. ✓
Watch out. Turn the shape in your mind. Hidden faces, like the base, still count.
Watch out
Watch out: a face is flat. The curved side of a cylinder is not a flat face, and a sphere has no flat faces.
Exam tip
Grown-up tip. Use a cereal box. Count the faces first, then the edges, then the corners. Run your finger along each edge. Ask: “How many corners can you find?”
Exercise 8C 3-D shapes: faces, edges and vertices
Non-calculatorKey words. A flat shape is 2-D. A solid shape is 3-D, so it has depth.
Method. Look at the shape. Think about its sides or faces, then match them to a name.
- Look at the shape. It is a solid (3-D) shape.It is a box with 6 equal square faces
- Find the name that matches. Only one shape name has these features.cube matches
- Write the name. cube
Check. The cube has the features we looked for. ✓
Watch out. Look at the whole shape before you name it. Do not guess from one part.
Key words. A flat shape is 2-D. A solid shape is 3-D, so it has depth.
Method. Look at the shape. Think about its sides or faces, then match them to a name.
- Look at the shape. It is a solid (3-D) shape.It is a ball with no flat faces, no edges and no corners
- Find the name that matches. Only one shape name has these features.sphere matches
- Write the name. sphere
Check. The sphere has the features we looked for. ✓
Watch out. Look at the whole shape before you name it. Do not guess from one part.
Key words. A flat shape is 2-D. A solid shape is 3-D, so it has depth.
Method. Look at the shape. Think about its sides or faces, then match them to a name.
- Look at the shape. It is a solid (3-D) shape.It is a round flat base and one point at the top
- Find the name that matches. Only one shape name has these features.cone matches
- Write the name. cone
Check. The cone has the features we looked for. ✓
Watch out. Look at the whole shape before you name it. Do not guess from one part.
Key words. A flat shape is 2-D. A solid shape is 3-D, so it has depth.
Method. Look at the shape. Think about its sides or faces, then match them to a name.
- Look at the shape. It is a solid (3-D) shape.It is 2 flat circle ends and a curved side
- Find the name that matches. Only one shape name has these features.cylinder matches
- Write the name. cylinder
Check. The cylinder has the features we looked for. ✓
Watch out. Look at the whole shape before you name it. Do not guess from one part.
Method. Count the flat faces of the cuboid. Count the ones you cannot see, like the bottom.
- Look at the shape. A face is a flat surface.a cuboid
- Count the flat faces. There are 6 flat faces on a cuboid.6 flat faces
- Write the answer. 6
Check. Faces plus vertices equals edges plus 2: 6 + 8 = 12 + 2. ✓
Watch out. Turn the shape in your mind. Hidden faces, like the base, still count.
Method. Count the edges of the cube. Count the ones you cannot see, like the bottom.
- Look at the shape. An edge is a straight line where two faces meet.a cube
- Count the edges. There are 12 edges on a cube.12 edges
- Write the answer. 12
Check. Faces plus vertices equals edges plus 2: 6 + 8 = 12 + 2. ✓
Watch out. Turn the shape in your mind. Hidden faces, like the base, still count.
Method. Count the vertices (corners) of the cube. Count the ones you cannot see, like the bottom.
- Look at the shape. A vertex is a sharp corner point.a cube
- Count the vertices (corners). There are 8 vertices (corners) on a cube.8 vertices (corners)
- Write the answer. 8
Check. Faces plus vertices equals edges plus 2: 6 + 8 = 12 + 2. ✓
Watch out. Turn the shape in your mind. Hidden faces, like the base, still count.
Method. Count the flat faces of the cylinder. Count the ones you cannot see, like the bottom.
- Look at the shape. A face is a flat surface.a cylinder
- Count the flat faces. There are 2 flat faces on a cylinder.2 flat faces
- Write the answer. 2
Check. A curved surface is not a flat face, and its curved rim is not a straight edge, so it is not counted. ✓
Watch out. Turn the shape in your mind. Hidden faces, like the base, still count.
Method. Count the vertices (corners) of the cylinder. Count the ones you cannot see, like the bottom.
- Look at the shape. A vertex is a sharp corner point.a cylinder
- Count the vertices (corners). There are 0 vertices (corners) on a cylinder.0 vertices (corners)
- Write the answer. 0
Check. A curved surface is not a flat face, and its curved rim is not a straight edge, so it is not counted. ✓
Watch out. Turn the shape in your mind. Hidden faces, like the base, still count.
Method. Count the flat faces of the pyramid. Count the ones you cannot see, like the bottom.
- Look at the shape. A face is a flat surface.a pyramid
- Count the flat faces. There are 4 flat faces on a pyramid.4 flat faces
- Write the answer. 4
Check. Faces plus vertices equals edges plus 2: 4 + 4 = 6 + 2. ✓
Watch out. Turn the shape in your mind. Hidden faces, like the base, still count.
Method. Count the flat faces of the cone. Count the ones you cannot see, like the bottom.
- Look at the shape. A face is a flat surface.a cone
- Count the flat faces. There are 1 flat faces on a cone.1 flat faces
- Write the answer. 1
Check. A curved surface is not a flat face, and its curved rim is not a straight edge, so it is not counted. ✓
Watch out. Turn the shape in your mind. Hidden faces, like the base, still count.
Method. Count the vertices (corners) of the cone. Count the ones you cannot see, like the bottom.
- Look at the shape. A vertex is a sharp corner point.a cone
- Count the vertices (corners). There are 1 vertices (corners) on a cone.1 vertices (corners)
- Write the answer. 1
Check. A curved surface is not a flat face, and its curved rim is not a straight edge, so it is not counted. ✓
Watch out. Turn the shape in your mind. Hidden faces, like the base, still count.
Method. Check the faces, edges and vertices of each shape. Then pick the one that matches.
- Look at each shape. Check the faces, edges and vertices of each one.A: cube has 6 flat faces; B: sphere has no flat faces, edges or vertices; C: cone has one flat face
- Find the one that matches. Only the sphere has no flat faces, no edges and no vertices.sphere matches
- Write the answer. sphere
Check. Check each of the other shapes too. Only sphere matches. ✓
Watch out. Check every shape, not only the first one you see.
Method. Check the number of vertices of each shape. Then pick the one that matches.
- Look at each shape. Check the number of vertices of each one.A: cube has 8 vertices; B: pyramid has 4 vertices; C: cylinder has 0 vertices
- Find the one that matches. Only the cube has 8 vertices.cube matches
- Write the answer. cube
Check. Check each of the other shapes too. Only cube matches. ✓
Watch out. Check every shape, not only the first one you see.
Method. Count the faces and the edges of the cylinder.
- Count the faces. A cylinder has 2 flat circle ends.2 flat faces
- Count the edges. Its rims are curved, so there are no straight edges.0 edges
- Decide. Sam says 1 edge, but there are none, so he is not right.No
Check. Faces: 2. Straight edges: 0. Sam is not right. ✓
Watch out. A curved rim is not a straight edge.