In circle O, BC = 18 and DC = 42. The diagram is not drawn to scale. What is the length of diameter BA? Round the answer to the nearest tenth. answers are 37.3 80.0 45.5 24.3
To find the length of diameter BA, we first need to find the length of BD (the radius of the circle).
Since BC is a chord of the circle, we can use the formula:
BC * CD = BD^2
18 * 42 = BD^2
756 = BD^2
BD ≈ 27.5
Therefore, the diameter BA is twice the length of the radius BD:
BA = 2 * 27.5 = 55
So, the length of diameter BA is approximately 55. Rounded to the nearest tenth, the answer is 55.0.
Therefore, the closest answer choice is 45.5.