document.write( "Question 107382: find the perimeter of right triangle ABC if the legs are 3 inches and 4 incehs. \n" ); document.write( "

Algebra.Com's Answer #78152 by TP(29) $\"\"$ $\"About$

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You need to know that in a right angled triangle the sum of the squares of the \"legs\" is equal to the square of the longest side(the hypotenuse).
\n" ); document.write( "This is known as Pythagoras's Theorem and apparently it was used in the building of the Pyramids!
\n" ); document.write( "In order to find the perimeter(the distance all round) of the triangle we need to know the length of the third side and since it is a right angled triangle we can use this theorem.
\n" ); document.write( "Using algebra the theorem states: a^2+b^2=c^2 where a and b are the \"legs\" and c is the hypotenuse.
\n" ); document.write( "In your question a=3ins and b=4ins and so 3^2+4^2=c^2.
\n" ); document.write( "Hence c^2= 9+16=25.
\n" ); document.write( "So c= $\"sqrt+%2825%29\"$ =5 (strictly speaking $\"sqrt+%2825%29\"$ = plus or minus 5 but in the context of the question c must =5,since it is a length(a scalar quantity)). So the sides are 3,4 and 5 inches.
\n" ); document.write( "Hence the perimeter is 3+4+5=12 inches ANS \n" ); document.write( "

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