Question

Use Euler’s Formula to find the missing number.

Edges: 43
Faces: 25
Vertices: ?

Answer 1

The answer is D, 23.

Answer 2

Vertices = 20

Explanation:

Using the Euler's formula:

V - E + F = 2 ....[1]

where,

E is the number of Edges

V is the number of Vertices

F is the number of Faces.

As per the statement:

Edges: 43

Faces: 25

⇒E = 43 and F = 25

Substitute in [1] we have;

`V-43+25 = 2`

⇒
`V-18 = 2`

Add 18 to both sides we have;

V = 20

Therefore, the number of vertices is, 20