SAT Math Multiple Choice Question 668: Answer and Explanation
The figure above shows a polygon with five sides. What is the average (arithmetic mean) of the measures, in degrees, of the five angles shown?
- A. 108°
- B. 110°
- C. 112°
- D. 114°
Correct Answer: A
Special Topics (polygons) EASY
The sum of the measures if the interior angles of any polygon is (n - 2)180°, where n is the number of sides in the polygon. Since this is a 5-sided polygon, the sum of its interior angles is (5 - 2)(180°) = 3(180°) = 540°. Therefore the average of these measures is 540°/5 = 108°.