document.write( "Question 326795: Find the area of an equilateral triangle that has a perimeter of 21 inches. Round the answer to one decimal place. Thank you. \n" ); document.write( "

Algebra.Com's Answer #234017 by jessica43(140) $\"\"$ $\"About$

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An equilateral triangle is a triangle with all three sides of equal length. So if we know the perimeter of a triangle is 21 inches, we can divide that by 3 to find the length of each side:
\n" ); document.write( "21/3 = 7
\n" ); document.write( "So each side of the triangle is 7 inches.
\n" ); document.write( "Now we will use the area of an equilateral triangle formula to solve the problem:
\n" ); document.write( "A = ((s^2)*(sqrt(3)))/4 where s = the length of a side
\n" ); document.write( "A = ((7^2)*(sqrt(3)))/4
\n" ); document.write( "A = (49*(sqrt(3)))/4
\n" ); document.write( "A = 21.2
\n" ); document.write( "So the area of the equilateral triangle is 21.2 square inches. \n" ); document.write( "

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