In a certain regular polygon, the measure of each interior angle is ten times the measure of each exterior angle. Find the number of sides in this regular polygon.
Sum of interior angles (n-2)(180)
then each interior angle (n-2)(180) / n
each exterior angle is 180 - (n-2)(180)/n
Now to the question (n-2)(180)/n ={ 180 - (n-2)(180)/n } *10
(180n- 360) ={ 180n - (n-2)(180) } * 10
180n - 360 = {180n - 180n + 360 } * 10
180n -360 = 3600
180 n = 3960
n = 22 interior angle = 163.636 exterior = 16.363
ANOTHER way:
10 n + n = 180
n = 16.363 = exterior angle
10n = interior = 163.636
(n-2)(180)/n = 163.636
180n - 360 = 163.636 n
n = 22
Sum of interior angles (n-2)(180)
then each interior angle (n-2)(180) / n
each exterior angle is 180 - (n-2)(180)/n
Now to the question (n-2)(180)/n ={ 180 - (n-2)(180)/n } *10
(180n- 360) ={ 180n - (n-2)(180) } * 10
180n - 360 = {180n - 180n + 360 } * 10
180n -360 = 3600
180 n = 3960
n = 22 interior angle = 163.636 exterior = 16.363
ANOTHER way:
10 n + n = 180
n = 16.363 = exterior angle
10n = interior = 163.636
(n-2)(180)/n = 163.636
180n - 360 = 163.636 n
n = 22