document.write( "Question 28995: If i have a retangle with 20 in diagonal with 30 degree on on sid what is the lenght and width of that retangle? \n" ); document.write( "
Algebra.Com's Answer #15833 by sdmmadam@yahoo.com(530)\"\" \"About 
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If i have a retangle with 20 in diagonal with 30 degree on on sid what is the lenght and width of that retangle?\r
\n" ); document.write( "\n" ); document.write( "I am sorry I am not able to bring my diagram over to the answer box here.
\n" ); document.write( "Please do as directed.
\n" ); document.write( "Draw a rough sketch of a rectangle.Mark it ABCD,with A as the left hand bottom corner vertex and then naming in order the other three vertices in the anti-clockwise direction.
\n" ); document.write( "Markdiagonal DB=20 and mark angle DBA = 30 degrees.
\n" ); document.write( "Concentrate your attention on the right angled triangle DAB.
\n" ); document.write( "Mark length AB = a and width AD =b
\n" ); document.write( "We have angle DAB=90 degrees,the acute angle DBA = 30 degrees.
\n" ); document.write( "and the hypotenuse DB=20
\n" ); document.write( "Using Pytho Theorem,we have
\n" ); document.write( " AB^2+DA^2= DB^2
\n" ); document.write( "a^2+b^2=20^2
\n" ); document.write( "a^2+b^2=400 ----(1)
\n" ); document.write( "Applying the tangent funtion to the angle DBA in this right angled triangle,
\n" ); document.write( "we have tan(30)= opp side/adjac side
\n" ); document.write( "1/[sqrt(3)] =(b/a)
\n" ); document.write( "which gives a =b[rt(3)] ---=-(2)
\n" ); document.write( "Using (2) in (1)
\n" ); document.write( "a^2+b^2=400
\n" ); document.write( "{b[rt(3)]}^2 + b^2 = 400
\n" ); document.write( "3b^2+b^2=400
\n" ); document.write( "4b^2=400
\n" ); document.write( "b^2=100 (dividing by 4)
\n" ); document.write( "b= 10
\n" ); document.write( "(taking only the positive sqrt as we are talking about sides of a rectangle)
\n" ); document.write( "Putting b=10 in (2),we have a =b[rt(3)]= 10[sqrt(3)]
\n" ); document.write( "Answer:Length of the rectangle = 10[sqrt(3)] and width = 10
\n" ); document.write( "Verification: we should get (length)^2+(width)^2 = (diagonal)^2
\n" ); document.write( "LHS= (length)^2+(width)^2
\n" ); document.write( "= {10[sqrt(3)]}^2 + 10^2 = (100X3) +100 = 400 = diagonal^2
\n" ); document.write( "Therefore our values are correct.\r
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