Given: CD is 20 cm long how long is the radius of the circle if the distance of CD from the center is:
1. 7cm
2. 10 cm
3. 13 cm
4. 8 cm
5. 5 cm
6. [tex]\sqrt{21} cm[/tex]
7. [tex]5\sqrt{5} cm[/tex]
8. [tex]4\sqrt{6} cm[/tex]