Square Within a Square

Nicole Mosteller

EMAT 6690


What happens to the area of square WXYZ as

point 1 moves out side of square ABCD?


Adaptations to be Made

To investigate the idea of point 1 moving out of the original square, a few adjustments needed to be made to the construction of our square. The original square was constructed onto a coordinate plane with the sides of the square extended to be lines. The sides of the inside square were reconstructed as well so that instead of segments, the sides are lines. The reconstruction does not effect the original property of the squares, but allows for further manipulation.

Graph 1: Squares on Coordinate Plane


To answer the original question, let's manipulate point 1 along line BA.

Graph 2: As point 1 moves in the negative direction from square ABCD, notice that square WXYZ grows larger. Infact while viewing the animation of point 1 along line AB (in the negative direction), square WXYZ seems to grows a maximum of twice as large as square ABCD. After reaching this peak, square WXYZ subsides and approaches the same area as square ABCD (See Graph 4).


Graph 3: As point one moves in the positive direction from square ABCD, notice that the square WXYZ continues to grow in area. While viewing the animation of point 1 along line AB (in the positive direction), square WXYZ's area continues to approach the area of the original square ABCD (See Graph 4).


In order to see exactly how the area of square WXYZ changes in respect to the area of square ABCD as point 1 moves along line AB, below is a graph of the trace of a point that shows the relationship.

Graph 4: After tracing a point that shows the relationship where

x = position of point 1 in respect to point B

y = the ratio of areas of squares WXYZ:ABCD,

our square problem has evolve from just a geometrical investigation of two squares to finding an algebraic representation of the relationship (x, y).


How do we find the equation for the line created by the traced point (x, y)?


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