How many sides does a regular polygon have if one interior angle measures [tex]$144^{\circ}$[/tex]?

[tex]$
n = [?]
$[/tex]

Hint: The measure of each interior angle in a regular [tex]$n$[/tex]-gon is [tex]$\frac{(n-2) \times 180}{n}$[/tex].



Answer :

To determine the number of sides [tex]\( n \)[/tex] in a regular polygon with each interior angle measuring [tex]\( 144^\circ \)[/tex], follow these steps:

1. Recall the formula for the interior angle of a regular [tex]\( n \)[/tex]-sided polygon:

[tex]\[ \text{Interior Angle} = \frac{(n-2) \times 180^\circ}{n} \][/tex]

2. Set the interior angle equal to [tex]\( 144^\circ \)[/tex]:

[tex]\[ 144 = \frac{(n-2) \times 180}{n} \][/tex]

3. Clear the fraction by multiplying both sides of the equation by [tex]\( n \)[/tex]:

[tex]\[ 144n = (n-2) \times 180 \][/tex]

4. Distribute the [tex]\( 180 \)[/tex] on the right side:

[tex]\[ 144n = 180n - 360 \][/tex]

5. Rearrange the equation to isolate [tex]\( n \)[/tex]:

[tex]\[ 144n - 180n = -360 \][/tex]

[tex]\[ -36n = -360 \][/tex]

6. Divide both sides by [tex]\( -36 \)[/tex]:

[tex]\[ n = \frac{360}{36} \][/tex]

7. Simplify the right side:

[tex]\[ n = 10 \][/tex]

So, the regular polygon has [tex]\( \boxed{10} \)[/tex] sides.