In the diagram shown on circle A, segment CD is tangent to the circle at point D. If CD=23 and CA=28, then which one of the following is closest to m∠C?

Answer:
m∠C = 35°
Step-by-step explanation:
Data
From the figure, it can be seen that a right triangle is formed where CA is the hypotenuse and CD is one of the legs.
From definition:
cos(C) = adjacent/hypotenuse
cos(C) = CD/CA
cos(C) = 23/28
m∠C = arccos(23/28)
m∠C = 35°
Answer:
(4) 35°.
Step-by-step explanation:
The value of the angle is given by the following inverse trigonometric function:
[tex]\theta = \cos^{-1}\left(\frac{CD}{CA} \right)[/tex]
[tex]\theta = \cos^{-1}\left(\frac{23}{28} \right)[/tex]
[tex]\theta \approx 34.772^{\circ}[/tex]
The right answer is (4) 35°.