Answer:
41.68 or 42 (rounded)
Step-by-step explanation:
Presuming you are working on right triangles, you can use the Soh Cah Toa theorems.
Because angle A = 21 and side a = 16 you can use Toa or 

Plugged into a calculator, you get 41.68 and some change.
If this is NOT a right triangle question, please let me know so that I can revise my answer.
Answer:
74.587, 74.586, 74.585, 75.486
Step-by-step explanation:
yes
Answer:
The displacement is: - 80 i
Step-by-step explanation:
In order to answer the question, you have to apply the displacement formula, which is:
ΔX= Xf-Xi
Where ΔX is the displacement, Xf is the final position and Xi is the initial position. The formula represents the change in the position of an object from the origin.
Let the origin be in 0 km,with the x-axis positive to te right.
Notice that the displacement is a vector. The positions are:
Xf=163 km (i)
Xi= 243 km (i)
Because John starts in 243 km and finishes in 163 km.
Where i is the unit vector in the x direction.
Therefore:
ΔX= 163 i - 243 i
Solving:
ΔX= -80 i
Notice that for calculating the displacement you just need the initial and final position. It doesn't depend on the distance traveled.