Answer:
b) ∠ACB = 25 degrees
Step-by-step explanation:
arc BA = 50° because central angle AOB = 50°
∠ACB is inscribed angle of 50°, so it is (1/2)(50) = 25°
See attached. The trick is to use similar triangles.
The geometric mean of two numbers x and y is √(xy).
So, if the geometric mean of 3 and a is 9 =>
9 = √(3a)
=> 9^2 = 3a
=> a = 9^2 / 3
a = 81 / 3
a = 27
Answer: the value of a is 27.
