Calculate the length of the fourth side edge.

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Discussion Overview

The discussion revolves around calculating the length of the fourth lateral edge of a pyramid with a square base, given the lengths of three lateral edges. The scope includes mathematical reasoning and problem-solving related to geometry and algebra.

Discussion Character

  • Mathematical reasoning

Main Points Raised

  • One participant presents the problem of finding the fourth edge length, providing the lengths of three edges and the assumption about their positions.
  • Another participant reiterates the problem and begins to set up a system of equations based on the positions of the pyramid's apex and the base corners.
  • This participant derives equations using the distance formula, suggesting that a unique integral value for the fourth edge length exists within a specific range.
  • Another participant expresses difficulty in solving the system due to the number of variables involved.
  • A later reply suggests a method to simplify the problem by subtracting equations to isolate the fourth edge length.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the solution, as one expresses difficulty in solving the equations while another proposes a method to simplify the calculations.

Contextual Notes

The discussion highlights the complexity of the system of equations and the potential for multiple variables to complicate the solution process.

ghostfirefox
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The three lateral edges of a pyramid based on a square are 6016, 2370 and 4350 long. Calculate the length of the fourth lateral edge. We assume that edges 6016 and 2370 extend from the opposite tops of the base.
 
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ghostfirefox said:
The three lateral edges of a pyramid based on a square are 6016, 2370 and 4350 long. Calculate the length of the fourth lateral edge. We assume that edges 6016 and 2370 extend from the opposite tops of the base.

let the four corners of the square base with side length $s$ lie in the x y plane with positions

$(0,0,0)$, $(s,0,0)$, $(s,s,0)$, and $(0,s,0)$

let the apex of the pyramid be at position $(a,b,c)$

... assume that edges 6016 and 2370 extend from the opposite tops of the base

using the distance formula between two points in space yields the following equations

$a^2+b^2+c^2 = 6016^2$
$(a-s)^2+(b-s)^2+c^2 = 2370^2$
$(a-s)^2+b^2+c^2=4350^2$
$a^2+(b-s)^2+c^2 = d^2$, where $d$ is the length of the fourth edge

use the system of equations to solve for $d$ ... I get a unique integral value for $d$ such that $4350 < d < 6016$
 
I tried to calculate this, but there are too many variables in this system of equations.
 
Subtract the 3rd equation from the 1st.

Subtract the 2nd equation from the 4th.

Work the solution for $d$ from the resulting two equations.
 

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