document.write( "Question 161696: The base of an isosceles triangle is one-third the length of each of the congruent sides. The perimeter of the triangle is 84 cm. How long is the base? \n" ); document.write( "

Algebra.Com's Answer #119174 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Calls the sides $\"S\"$
\n" ); document.write( "Call the base $\"B\"$
\n" ); document.write( "The perimeter is then $\"S+%2B+S+%2B+B\"$
\n" ); document.write( " $\"S+%2B+S+%2B+B+=+84\"$
\n" ); document.write( "It is given that
\n" ); document.write( " $\"B+=+%281%2F3%29%2AS\"$ , so
\n" ); document.write( " $\"S+%2B+S+%2B+%281%2F3%29%2AS+=+84\"$
\n" ); document.write( "Multiply both sides by $\"3\"$
\n" ); document.write( " $\"3%2A2%2AS+%2B+S+=+252\"$
\n" ); document.write( " $\"7S+=+252\"$
\n" ); document.write( " $\"S+=+36\"$
\n" ); document.write( " $\"B+=+%281%2F3%29%2AS\"$
\n" ); document.write( " $\"B+=+%281%2F3%29%2A36\"$
\n" ); document.write( " $\"B+=+12\"$ cm
\n" ); document.write( "check:
\n" ); document.write( " $\"S+%2B+S+%2B+B+=+84\"$
\n" ); document.write( " $\"36+%2B+36+%2B+12+=+84\"$
\n" ); document.write( " $\"84+=+84\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );