FACES EDGES VERTICES

Write the number of faces, edges, and vertices, and identify each 3D shape.

Problem 1 :

Solution :

Number of vertices :

Marking vertices, number of vertices for a pentagonal prism is 10.

Number of faces :

Side = 5 faces

Top and bottom = 2 faces

Total faces = 7

Number of edges :

Edges = 15

Problem 2 :

Solution :

Number of vertices :

One vertex at the top.

Number of faces :

Curved face = 1

bottom face = 1

Total faces is 2.

Number of edges :

A cone has one flat surface and one curved surface. Number of edges of cone is 1.

Problem 3 :

Solution :

Number of vertices :

There is no vertices.

Number of faces :

Curved face = 1

bottom face = 1

Top face = 1

Total faces is 3.

Number of edges :

Curved surface is connected with top face to the bottom face, so number of edges is 2.

Problem 4 :

Solution :

Number of vertices :

Number of corners for rectangle = 4, at top we have 1

Total vertices = 4 + 1 => 5

Number of faces :

Curved face = 4

bottom face = 1

Total faces is 5.

Number of edges :

Number of edges = 8

Problem 5 :

Solution :

Number of vertices :

Number of corners for rectangle = 4, at top = 2

Total vertices = 4 + 2 => 6

Number of faces :

Front face = 1

back face = 1

side face = 2

bottom face = 1

Total faces = 1 + 1 + 2 + 1 ==> 5

Total faces is 5.

Number of edges :

Number of edges = 9

Problem 6 :

Solution :

Number of vertices :

Number of vertices = 0

Number of faces :

There is curved surface. So, total faces = 1.

Number of edges :

Number of edges = 0

Problem 7 :

Solution :

Number of vertices :

Number of rectangle at the top = 4

Number of rectangle at bottom = 4

Number of vertices = 4 + 4 ==> 8

Number of faces :

Side faces = 2

Top and bottom = 2

Front and back = 2

Total faces = 2 + 2 + 2 ==> 6

Number of edges :

Number of edges = 12

Problem 8 :

Solution :

Number of vertices :

Number of corners in triangle = 3

At top, we have 1

Total vertices = 3 + 1 ==> 4

Number of faces :

Side faces = 3

bottom = 1

Total faces = 3 + 1 ==> 4

Number of edges :

Number of edges = 6

Problem 9 :

How many triangles has a square pyramid?

Solution :

The square pyramid has 4 triangular faces.

Problem 9 :

Which 3D shape has 1 curved surface and 1 flat surface?

Solution :

The 3D shape cone which has one curved face and one flat face.

Problem 10 :

How many edges has a triangular prism?

Solution :

A triangular prism has 9 edges.

Problem 11 :

The names of six 3-D shapes are given below. Three of them are drawn below A 

Cube       Cuboid      Sphere        Cylinder

Triangular Prism          Cone

Solution :

• Shape A is cuboid
• Shape B is cylinder
• Shape C is sphere

Problem 12 :

Chloe has drawn a 3-D shape. Her shape has 5 vertices. It has 8 edges. It has 5 faces. What 3-D shape has Chloe drawn?

Solution :

• Number of faces = 5
• Number of vertices = 5
• Number of edges = 8

So, the required shape is square base prism.

Problem 13 :

Edward has drawn a 3-D shape. His shape has 6 vertices. It has 9 edges. It has 5 faces. What 3-D shape has Edward drawn?

Solution :

• Number of faces = 5
• Number of vertices = 6
• Number of edges = 9

So, the required shape is triangular prism.

Problem 14 :

Match the pictures to the descriptions and name the shapes.

a) I have 5 faces and 5 corners. I have 8 edges. 1 of my faces is a square and 4 of my faces are triangles..………….

b) I have 1 flat face, 1 curved face, and 1 edge.………….

c) I have 1 curved face. I have no edges or corners.…….

d) I have 2 flat faces, 1 curved face, and 2 edges. I have no corners.………….

e) I have 5 faces, 6 corners, and 9 edges, and 2 of my faces are triangles.………….

f) I have 6 faces, 12 edges, and 8 corners.…………

Solution :

a) Square base pyramid.

b) Cone

c) Sphere

d) Cylinder

e) Triangular prism.

f) Cube.