Which of the following cannot be interior angle of a regular polygon?
[#permalink]
02 Apr 2021, 18:55
To find the sum of all interior angles of a polygon with n sides, we use the equation, sum of interior angles = (n-2) * 180. To find each angle of regular polygon, we divide this sum by n. Let's use this in this question.
If x is measure of interior angle,
[(n-2) * 180] / n = x
[180n - 360] / n = x
180 - (360/n) = x
180 - x = 360 / n
n = 360 / (180 - x)
Now plugin each answer choice for x. If n turns out to be an integer, eliminate because number of sides n must be an integer.
Only for x = 125 you will find n ≠ integer.
Hence, E is the correct answer.
Posted from my mobile device