The size of an interior angle of a n-sided polygon is 14 times of its exterior angle.Find the value of n
HOW TO SOLVE?
The interior angle is given by : (n-2) (180)/ n
And the exterior angle is given by : 360/n
And we have that
(n - 2) (180) / n = 14* 360/ n [multiply both sides by n and simplify ]
180n -360 = 5040 add 360 to both sides
180n = 5400 divide both sides by 180
n = 30
The size of an interior angle of a n-sided polygon is 14 times of its exterior angle.Find the value of n
HOW TO SOLVE?
The Exterior Angles of a Polygon add up to \( 360^{\circ} \qquad sum_e = 360^{\circ}\)
Sum of Interior Angles \( = (n-2) × 180^{\circ}\qquad sum_i = (n-2) \cdot 180^{\circ}\)
\(\begin{array}{rcll} sum_i &=& 14 \cdot sum_e \\ (n-2) \cdot 180^{\circ} &=& 14 \cdot 360^{\circ} \quad & | \quad :180 \\ n-2 &=& 14 \cdot \frac{ 360^{\circ} } { 180^{\circ} } \\ n-2 &=& 14 \cdot 2 \\ n-2 &=& 28 \quad & | \quad +2 \\ \mathbf{ n } & \mathbf{=} & \mathbf{30} \\ \end{array}\)