2:B

3:D

4:C

5:B

6:D

7:8

8: 1 15 degrees

six to ten

10:B

1 1:B

12: COnnect AO, BO and co and do it yourself.

13: Because AF bisects BE vertically, AB equals AE. So triangle ABE is an isosceles triangle. So the angle ABD+ the angle DBE is equal to the angle AED. Because the angle CBD is bisected, the angle DBE is equal to the angle EBC. Because angle EBC+ angle C equals AEB and angle ABD equals angle C.