Question 199738
The Pythagorean Theorem is wriiten as follows:
{{{a^2+b^2=c^2}}}
Where:
a = one side of a right triangle
b = the other side of a right triangle
c = the hypoteneuse (diagonal) of a right trianagle

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Note that this equation applies only to right triangles - which is a triangle which has one angle of 90 degrees. The hypoteneuse is the side of the triangle opposite this 90 degree angle.

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So back to the problem... the goal is to make sure that the walls of the building are "square." That means that they form a 90 degree angle. So let's apply the pythagorean theorem to prove that if the 2 walls are length 3 and 4 respectively, the diagonal is 5.

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Pythagorean Theorem:
{{{a^2+b^2=c^2}}}

Substitute in your given values:
{{{3^2+4^2=c^2}}}

Simplify:
{{{9+16=c^2}}}
{{{c^2=25}}}
{{{sqrt(c^2)=sqrt(25)}}}
{{{highlight(c=5)}}}

So you have proven that the diagonal is 5. Thus from the given information in the problem, you also know that the walls form a right angle.

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Good Luck,
tutor_paul@yahoo.com