Answer:
A, C
Step-by-step explanation:
Use SOH CAH TOA to recall how the trig functions fit on a triangle
SOH: Sin(Ф)= Opp / Hyp
CAH: Cos(Ф)= Adj / Hyp
TOA: Tan(Ф) = Opp / Adj
the ∠A is adjacent (adj) to AB and opposite (Opp) of BC and AB is the hypotenuse (Hyp) of the triangle
which one of the above trig functions fits that?
sin(Ф) = BC / AC is sin(Ф)= Opp / Hyp , so choice A) works
cos(Ф) = BC / AC is not cos(Ф) = Opp / Hyp so choice B) does not work
cos(Ф) = BA / AC is cos(Ф) = Adj / Hyp so choice C) works
AC / BC is just a ratio it's not the angle , so D) doesn't work
