Answer:
m∠I = 58.4°
Step-by-step explanation:
cos = adjacent side/hypotenuse
It is always helpful to have a picture. In your case KI is adjacent to ∠I and IJ is the hypotenuse.
So cos I = KI/IJ = 4.5/8.6
arccos (4.5/8.6) = m∠I
m∠I = 58.4°
It is necessary for you to memorize the definitions of the trig functions in order to do these types of problems. OK?
