CD is tangent to circle O at D. Find the diameter of the circle for BC = 13 and DC = 30. Round to the nearest tenth. (The diagram is not drawn to scale.)

Question

anonymous · Answer

https://study.ashworthcollege.edu/access/content/group/45b8c516-1008-46d7-aa1d-bb9b62c786ff/geometry_exam_12_files/mc013-2.jpg

directrix · Answer

The theorem you need to solve this problem is attached below.

anonymous · Answer

I see that but i really dont get how to do it.

anonymous · Answer

wait! 13(13=30)

anonymous · Answer

13(13+30)

directrix · Answer

See if you can solve the equation.

30² = 13( 13 + x) where x = AB, the diameter of the circle.

anonymous · Answer

Ohh...Okay

anonymous · Answer

56.23

directrix · Answer

On the equation you wrote, you forgot to square the tangent length.

anonymous · Answer

Oh i see

anonymous · Answer

Is 56 right?

directrix · Answer

56.231 for x = AB which is the diameter is what I got. Same as your answer.

directrix · Answer

Round to the nearest tenth.

anonymous · Answer

Okay thanks! Can you help me out with some other ones too please?

directrix · Answer

What is 56.231 to the nearest tenth?

anonymous · Answer

56.2

directrix · Answer

Yes.

directrix · Answer

Close this thread and post your next question in a new thread.

anonymous · Answer

Circle O and circle P are congruent. What can you conclude from the diagram? https://study.ashworthcollege.edu/access/content/group/45b8c516-1008-46d7-aa1d-bb9b62c786ff/geometry_exam_12_files/mc001-1.jpg

anonymous · Answer

Please help...

directrix · Answer

I think you need the theorem that begins: In the same circle or in congruent circles, congruent central angles have ________________________________?  That would be, I think, what you could conclude. But, first look up that theorem.

anonymous · Answer

The same measure?