18. What do you call a polygon with nine sides? a. quadrilateral b. pentagon c. hexagon d. nonagon
19. Which of the following represents a plane? a. pencil b. bulletin board c. corner of a sheet of paper d. edge of a sidewalk
20. What do you call the common end point of the two different rays forming an angle? a. segment b. vertex c. midpoint d.bisector
21. What is the sum of the measure of the two angles if they are supplementary? a. 180° b. 360° 0.450 d. 90°
22. Find the sum of the measures of the interior angles of a convex polygon with 18 sides. a. 810° b. 10800 C. 16200 d. 2880°
23. Each exterior angle of a regular polygon has a measure of 40. How many sides does the regular polygon have? a. 8 b. 9 c. 10 d. 11
24. How many sides does a convex polygon have the sum of the measure of its angles is 2,160? a. 14 b. 13 c. 12 d. 11 25. If you are going to cut a rectangular wood into triangles once, how many triangles can be formed? b. 2 d. 4 a. 1 GS​