Tabulate THREE advantages and disadvantages of compass surveying and calculate the volume of excavated material.

The coordinates are given as (Y, X). For area calculation using the shoelace formula, we typically use (X, Y).
R1: $(X_1, Y_1) = (209.90, 105.10)$
R2: $(X_2, Y_2) = (320.75, 130.32)$
R3: $(X_3, Y_3) = (540.20, 305.70)$
R4: $(X_4, Y_4) = (600.24, 506.50)$

The formula for the area $A$ of a polygon with $n$ vertices is:

where $(X_{n+1}, Y_{n+1}) = (X_1, Y_1)$.

Calculate the sum of $(X_i Y_{i+1})$ terms:
$X_1 Y_2 = 209.90 \times 130.32 = 27351.468$
$X_2 Y_3 = 320.75 \times 305.70 = 98040.075$
$X_3 Y_4 = 540.20 \times 506.50 = 273491.300$
$X_4 Y_1 = 600.24 \times 105.10 = 63085.224$
Sum $(X_i Y_{i+1}) = 27351.468 + 98040.075 + 273491.300 + 63085.224 = 461968.067$

Calculate the sum of $(X_{i+1} Y_i)$ terms:
$X_2 Y_1 = 320.75 \times 105.10 = 33711.325$
$X_3 Y_2 = 540.20 \times 130.32 = 70409.864$
$X_4 Y_3 = 600.24 \times 305.70 = 183503.208$
$X_1 Y_4 = 209.90 \times 506.50 = 106314.350$
Sum $(X_{i+1} Y_i) = 33711.325 + 70409.864 + 183503.208 + 106314.350 = 393938.747$

Now, calculate the area $A$:

Ground level $= 90 \text{ m}$
Reduced level (excavated) $= 67 \text{ m}$
Depth $D = \text{Ground level} - \text{Reduced level}$

Volume $V = \text{Area} \times \text{Depth}$

The volume of the material that has been excavated is $\boxed{\text{782337.18 m}^3}$.