Pirate Island Bedf53
1. **Problem statement:** We have a circular island centered at $P(0,0)$ with radius 8 km. Four pirates want to divide the island into four equal areas by placing their bases so that the boundaries are the perpendicular bisectors between their bases.
2. **Step (a): Find coordinates of the four pirates' bases for equal area cells.**
- Since the island is a circle centered at the origin, dividing it into four equal areas means dividing it into four equal sectors of 90° each.
- The bases should be placed on the circle at points equally spaced by 90°.
- Coordinates on a circle of radius 8 km at angles $0^\circ$, $90^\circ$, $180^\circ$, and $270^\circ$ are:
- Pirate 1: $(8,0)$
- Pirate 2: $(0,8)$
- Pirate 3: $(-8,0)$
- Pirate 4: $(0,-8)$
3. **Step (b): Calculate the area of each pirate's cell.**
- The total area of the island is $A = \pi r^2 = \pi \times 8^2 = 64\pi$ km$^2$.
- Dividing into 4 equal parts, each cell area is:
$$\frac{64\pi}{4} = 16\pi \approx 50.3 \text{ km}^2$$
4. **Step (c): A fifth pirate arrives at the center $P(0,0)$ and sets up a base. Calculate the percentage of land each original pirate must give up.**
- The fifth pirate's base at the center creates new boundaries.
- The original four pirates' cells are now divided by the captain's base.
- The captain's cell is a smaller circle or polygon around the center.
- Since the captain is at the center, the original four cells lose equal parts of their land.
- The captain's cell area is a circle with radius equal to half the distance between the center and each pirate base (which is 8 km), so radius is 4 km.
- Area of captain's cell:
$$\pi \times 4^2 = 16\pi \approx 50.3 \text{ km}^2$$
- Total island area is $64\pi$, so captain's share is $\frac{16\pi}{64\pi} = \frac{1}{4} = 25\%$.
- Each original pirate loses $\frac{25\%}{4} = 6.25\%$ of their land to the captain.
**Final answers:**
- (a) Pirates' bases coordinates: $(8,0)$, $(0,8)$, $(-8,0)$, $(0,-8)$
- (b) Area of each pirate's cell: $16\pi \approx 50.3$ km$^2$
- (c) Each original pirate gives up $6.25\%$ of their land to the captain.