SOLUTION: How many squares in the plane have at least two points in the lattice below as vertices? https://www.svgrepo.com/show/446596/four-dots-square.svg

Algebra ->  Permutations -> SOLUTION: How many squares in the plane have at least two points in the lattice below as vertices? https://www.svgrepo.com/show/446596/four-dots-square.svg      Log On


   



Question 1210196: How many squares in the plane have at least two points in the lattice below as vertices?
https://www.svgrepo.com/show/446596/four-dots-square.svg

Found 3 solutions by CPhill, ikleyn, greenestamps:
Answer by CPhill(1959) About Me  (Show Source):
You can put this solution on YOUR website!
```
* *
* *
```
Let's break down this problem.
**1. Lattice Points**
The given lattice points are:
* (0, 0)
* (1, 0)
* (0, 1)
* (1, 1)
**2. Squares with at Least Two Points as Vertices**
We need to count the squares that can be formed using at least two of these points as vertices.
* **Squares with All Four Points as Vertices:**
* There is only 1 such square, the one formed by the four given points.
* **Squares with Two Points as Vertices:**
* **Squares with Sides Parallel to Axes:**
* The square with side length 1 is the only such square we have already counted.
* **Tilted Squares:**
* Consider the segment connecting (0, 0) and (1, 1). This is a diagonal of a square.
* Consider the segment connecting (1, 0) and (0, 1). This is also a diagonal of a square.
* These diagonals form a square with area 2.
* The vertices of this square are:
* (0, 0), (1, 1), (0, 2), (-1, 1)
* (0, 0), (1, 1), (2, 0), (1, -1)
* (0, 1), (1, 0), (2, 1), (1, 2)
* (0, 1), (1, 0), (-1, 0), (0, -1)
* We are only concerned with the squares that have at least 2 points from the lattice as vertices.
* The square with the diagonal from (0,0) to (1,1) has (0,0) and (1,1) as vertices.
* The square with the diagonal from (1,0) to (0,1) has (1,0) and (0,1) as vertices.
* The square with the diagonal from (1,1) to (0,0) has (1,1) and (0,0) as vertices.
* The square with the diagonal from (0,1) to (1,0) has (0,1) and (1,0) as vertices.
* Thus we have one square with at least 2 vertices.
**3. Counting All Squares**
* **1 Square** with all four points as vertices.
* **1 Square** with two points as vertices and is tilted.
**Total Squares**
* 1 + 1 = 2
**Therefore, there are 2 squares in the plane that have at least two points in the lattice as vertices.**

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
How many squares in the plane have at least two points in the lattice below as vertices?
https://www.svgrepo.com/show/446596/four-dots-square.svg
~~~~~~~~~~~~~~~~~~~~~~~~~~


Looking at the picture under the link, I do not understand,
how does it relate to the text in the post.

The referred picture is only good to scare people around.



Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


The AI solution from the other "tutor" makes no sense....

There is obviously only one square that has all four of those points as vertices.

There are obviously no squares that have exactly 3 of those 4 points as vertices.

For each pair of lattice points in the array that are adjacent vertically or horizontally, there is a square, outside of the given array, containing exactly those two given lattice points. That's 4 more squares containing exactly 2 of the given lattice points.



For each pair of lattice points in the array that are diagonally opposite, there are 2 squares, outside of the given array, containing exactly those two given lattice points. That's 4 more squares containing exactly 2 of the given lattice points.





So the total number of squares in the plane that have at least two of the given lattice points as vertices is 1+4+4 = 9.

ANSWER: 9