Algebra Find the value of x to the nearest tenth.

B Apply

16. Geometry in 3 Dimensions In the figure below, sphere O with radius 13 cm is intersected by a plane 5 cm from center O. Find the radius of the cross section ⊙ A . circle dot eh .

    

17. Geometry in 3 Dimensions A plane intersects a sphere that has radius 10 in., forming the cross section ⊙ B circle dot b  with radius 8 in. How far is the plane from the center of the sphere?
18. Think About a Plan Two concentric circles have radii of 4 cm and 8 cm. A segment tangent to the smaller circle is a chord of the larger circle. What is the length of the segment to the nearest tenth?
    • How will you start the diagram?
    • Where is the best place to position the radius of each circle?

19. Proof Prove Theorem 12-4.

    Given: ⊙ O circle dot o  with ∠ A O B ≅ ∠ C O D angle , eh o b approximately equal to , angle c o d

    Prove: A B ⌢ ≅ C D ⌢ modified eh b with frown above , approximately equal to , modified c d with frown above

    

20. Proof Prove Theorem 12-5.

    Given: ⊙ O circle dot o  with ∠ A O B ≅ ∠ C O D angle , eh o b approximately equal to , angle c o d

    Prove: A B ¯ ≅ C D ¯ eh b bar , approximately equal to , c d bar

    

21. Proof Prove Theorem 12-6.

    Given: ⊙ O circle dot o  with A B ¯ ≅ C D ¯ eh b bar , approximately equal to , c d bar

    Prove: A B ⌢ ≅ C D ⌢ modified eh b with frown above , approximately equal to , modified c d with frown above

    

22. Proof Prove Theorem 12-8.

    Given: ⊙ O circle dot o  with diameter E D ¯ ⊥ A B ¯ e d bar , up tack , eh b bar  at C

    Prove: A C ¯ ≅ B C ¯ , A D ⌢ ≅ B D ⌢ eh c bar , approximately equal to . b c bar , comma . modified eh d with frown above , approximately equal to , modified b d with frown above

    

⊙ A circle dot eh  and B are congruent. C D ¯ c d bar  is a chord of both circles.

23. If A B = 8  in . eh b equals 8 in .  and C D = 6  in . , c d equals 6 in . comma  how long is a radius?
24. If A B = 24  cm eh b equals 24 , cm  and a radius = 13 cm , equals 13 cm comma  how long is C D ¯ ? c d bar , question mark
25. If a radius = 13  ft radius , equals 13 , ft  and C D ¯ = 24  ft , c d bar . equals 24 , ft comma  how long is A B ¯ ? eh b bar , question mark

26. Construction Use Theorem 12-5 to construct a regular octagon.

Table of Contents