A 20-sided regular polygon has an angle measure represented as [tex]$39^{\circ}$[/tex].

Determine the value of [tex]$g$[/tex].
A. [tex]$g=180$[/tex]
B. [tex]$g=162$[/tex]
C. [tex]$g=60$[/tex]
D. [tex]$g=54$[/tex]



Answer :

To solve the given problem, let's analyze the interior angles of a regular 20-sided polygon.

1. Formula for the Interior Angle of a Regular Polygon:

The formula to determine the measure of an interior angle of a regular [tex]\( n \)[/tex]-sided polygon is:
[tex]\[ \text{Interior angle} = \frac{(n-2) \times 180^\circ}{n} \][/tex]
Where [tex]\( n \)[/tex] is the number of sides of the polygon.

2. Substitute [tex]\( n = 20 \)[/tex]:

For a 20-sided polygon ([tex]\( n = 20 \)[/tex]):
[tex]\[ \text{Interior angle} = \frac{(20-2) \times 180^\circ}{20} \][/tex]

3. Calculate the Interior Angle:

[tex]\[ \text{Interior angle} = \frac{18 \times 180^\circ}{20} \][/tex]
[tex]\[ \text{Interior angle} = \frac{3240^\circ}{20} \][/tex]
[tex]\[ \text{Interior angle} = 162^\circ \][/tex]

4. Match the Interior Angle with the Given Choices:

Among the given choices for [tex]\( g \)[/tex]:
[tex]\[ g = 180^\circ, \quad g = 162^\circ, \quad g = 60^\circ, \quad g = 54^\circ \][/tex]
The calculated interior angle of the 20-sided polygon is [tex]\( 162^\circ \)[/tex]. Therefore, the value that matches the interior angle of the polygon from the given choices is:
[tex]\[ g = 162 \][/tex]

Thus, the value of [tex]\( g \)[/tex] is [tex]\( \boxed{162} \)[/tex].