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)![]() ![]() ![]() You can put this solution on YOUR website! 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 \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |