Answer:
D) 41.81 degrees
Explanation:
In this problem, we are given a leg length (a=12) and the hypotenuse (c=18).
We need to select which trigonometric identity to use with the acronym SOHCAHTOA:
SOH -> sine=opposite/hypotenuse
CAH -> cosine=adjacent/hypotenuse
TOA -> tangent=opposite/adjacent
Given side a is opposite of angle A and side c is the hypotenuse, we clearly need to use the sine function.
Set up an equation based on the information you have:
sin(A)=12/18
Now take the inverse:
sin^-1(sin(A))=sin^-1(12/18)
A=41.8103149
So the best option is answer D) 41.81 degrees