Question

what is the measure of one interior angle of a regular 13-gon? (round to the nearest tenth if necessary)

152.3
147.5
150.4
158.2

Explanation:

Calculate the sum of interior angles

Using the Regular Polygon Angles knowledge point

$$ S = (n - 2) \times 180^\circ $$

$$ S = (13 - 2) \times 180^\circ = 11 \times 180^\circ = 1980^\circ $$

Determine the measure of one interior angle

Using the Regular Polygon Angles knowledge point

$$ I = \frac{S}{n} = \frac{1980^\circ}{13} \approx 152.30769^\circ $$

Round to the nearest tenth

Using the Regular Polygon Angles knowledge point

$$ I \approx 152.3^\circ $$

Answer:

• (A) 152.3 (Correct answer)
• (B) 147.5
• (C) 150.4
• (D) 158.2