Question 222521
Find the exact length of the side of a square whose diagonal is 3 feet


Step 1.  Let s be the side and note the diagonal breaks the square into two equivalent right triangels.


Step 2.  Use the Pythagorean Theorem to find the side where the sum of the square of the legs is equal to the square of the hypotenuse (or 3 feet in this example).


Legs are two sides each of length s so


{{{s^2+s^2=3^2}}}


{{{2s^2=3^2}}}


Divide 2 to both sides of the equation


{{{2s^2/2=3^2/2}}}


{{{s^2=3^2/2}}}


Take the square root to both sides of the equation


{{{s=3/sqrt(2)}}}


{{{s=3sqrt(2)/sqrt(2)sqrt(2)}}}


{{{s=3sqrt(2)/2}}}


Step 3.  ANSWER:  The side {{{s=3sqrt(2)/2}}}


I hope the above steps were helpful.


For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.


Good luck in your studies!


Respectfully,
Dr J