13. Which could be the measurement of an acute angle? A. 35° B. 90° C. 180° D. 360° 14. What kind of angle is formed by the corner of a square table? A. acute angle B. obtuse angle C. right angle D. straight angle 15. What kind of angle is shown by an opened book whose measure is greater than 90°? A. acute angle B. obtuse angle C. right angle D. straight angle 16. Which property allows you to name a quadrilateral? A. five sided figure C. three sided figure B. four sided figure D. two sided figure 17. Which of the following is not a polygon? A. quadrilateral B. pentagon C. semi-circle D. pentagon 18.How many sides does a triangle have? A. three B. four C. five D. six 19.What is the sum of the interior angle in a triangle? A. 90° B. 180° C. 220° D. 360° 20.What is a polygon? A closed figure made up of crossed line segments B. A closed figure made up of straight line segments C. An open figure made up of crossed line segments D. An open figure made up of straight line segments​