11. How many sides does a decagon have?
A. 7
B. 8
C. 9
D. 10
12. What is the sum of the measures of the angles of a triangle?
A. 90°
B. 180°
C. 270°
D. 360°
13. What do you call a triangle with three congruent sides?
A. equiangular B. equilateral
C. isosceles D. scalene
14. What is the sum of the measures of the angles of a quadrilateral?
A. 90°
B. 180°
C. 2709
D. 360°
15. How many vertices does a regular heptagon have?
A. 6
B. 7
C. 8
D. 9​