document.write( "Question 114986: Carpentry:
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document.write( "The perimeter of the rectangular window is 14 ft. and its length is 2 ft less than twice the width. What are the dimensions of the window? \n" );
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Algebra.Com's Answer #83654 by bucky(2189)![]() ![]() ![]() You can put this solution on YOUR website! The perimeter of a plane figure is the sum of the lengths of its sides. Since you are told \n" ); document.write( "that the figure is a rectangle you know that its sides are its length (call it L) and its \n" ); document.write( "width (call it W) and by the definition of a rectangle there are two lengths and two widths. \n" ); document.write( ". \n" ); document.write( "Therefore, you can write an equation for the perimeter (call it P) as: \n" ); document.write( ". \n" ); document.write( "P = 2L + 2W \n" ); document.write( ". \n" ); document.write( "And since you are told that the perimeter is 14 feet, you can substitute 14 for P to make \n" ); document.write( "the equation become: \n" ); document.write( ". \n" ); document.write( "14 = 2L + 2W \n" ); document.write( ". \n" ); document.write( "Next you are told that its length is 2 feet less than twice its width. If the length equaled \n" ); document.write( "twice its width you could say L = 2W, but the length is 2 feet less than 2W. So you can \n" ); document.write( "write this equation as: \n" ); document.write( ". \n" ); document.write( "L = 2W - 2 \n" ); document.write( ". \n" ); document.write( "Now you can return to the perimeter equation and substitute 2W - 2 for L because they are \n" ); document.write( "equals. The perimeter equation is: \n" ); document.write( ". \n" ); document.write( "14 = 2L + 2W \n" ); document.write( ". \n" ); document.write( "Replace L with the quantity 2W - 2 and this equation becomes: \n" ); document.write( ". \n" ); document.write( "14 = 2(2W - 2) + 2W \n" ); document.write( ". \n" ); document.write( "Multiply out the first term on the right side of this equation and the equation becomes: \n" ); document.write( ". \n" ); document.write( "14 = 4W - 4 + 2W \n" ); document.write( ". \n" ); document.write( "On the right side combine the 4W and the +2W to get 6W and the equation then is: \n" ); document.write( ". \n" ); document.write( "14 = 6W - 4 \n" ); document.write( ". \n" ); document.write( "Get rid of the -4 on the right side by adding +4 to both sides of the equation and the \n" ); document.write( "equation then is: \n" ); document.write( ". \n" ); document.write( "18 = 6W \n" ); document.write( ". \n" ); document.write( "Solve for W by dividing both sides of the equation by 6 and you have: \n" ); document.write( ". \n" ); document.write( "3 = W \n" ); document.write( ". \n" ); document.write( "So W is 3 feet. Since there are two widths in the rectangle, the combined widths are 6 \n" ); document.write( "feet. Take that away from the perimeter and you have 14 - 6 = 8 feet. This remaining \n" ); document.write( "8 feet is the dimension for the two lengths of the rectangle. So each length must be \n" ); document.write( "half of 8 feet ... or you can say that the length of the window is 8 divided by 2 and this \n" ); document.write( "is 4 feet. \n" ); document.write( ". \n" ); document.write( "In summary, the width of the window is 3 feet and the length of the window is 4 feet. \n" ); document.write( ". \n" ); document.write( "Check: The perimeter of the window is to be 14 feet. Add up the lengths and the widths: \n" ); document.write( "4 + 4 + 3 + 3 and the sum is 14. So that requirement checks. \n" ); document.write( ". \n" ); document.write( "Next the length is to be 2 feet less than twice the width. Twice the width is 2 times 3 \n" ); document.write( "which is 6 feet. Is the length (4 feet) 2 feet less than 6 feet. Yes, it is. So the answers \n" ); document.write( "check out. \n" ); document.write( ". \n" ); document.write( "Hope this helps you to see your way through the problem. \n" ); document.write( ". \n" ); document.write( " |