What are Vertices ?
What are edges ?
An edge in a shape can be defined as a point where two faces meet.
What are faces ?
Every individual flat surface of a solid is called its face. Solids have more than one face.
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
May 21, 24 08:51 PM
May 21, 24 08:51 AM
May 20, 24 10:45 PM