Depends on what the area is. If it’s a rural place, Wood is cheep & easy to build. If there’s a lot of corrosion, strong weather/hurricane, bricks.
What website are you using?
Answer:
48.4 km, 34.3° north of east
Explanation:
Let's say east is the +x direction and north is the +y direction.
Adding up the x components of the vectors:
x = 20 cos 60 + 30 + 0
x = 40 km
Adding up the y components of the vectors:
y = 20 sin 60 + 0 + 10
y = 27.3 km
The magnitude of the displacement is:
d = √(x² + y²)
d = 48.4 km
The direction is:
θ = atan(y/x)
θ = 34.3° north of east
The one at the base would be much older due to the law of super position, and the rock at the top would be much newer,again, due to the law of super position.