document.write( "Question 1094389: In rectangle ABCD, diagonal BD = 26 cm and cotangent of angle ABD = 1.5. Find the area and the perimeter of the rectangle ABCD. \n" ); document.write( "
Algebra.Com's Answer #708965 by hgv (5)![]() ![]() You can put this solution on YOUR website! Given in the question;\r \n" ); document.write( "\n" ); document.write( "Cotangent (Cot)ABD = 1.5 \n" ); document.write( "can be written as Cot ABD = AB/AD => 3/2\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " [Cot = Perpendicular/Base]\r \n" ); document.write( "\n" ); document.write( "=> AB = 3x, AD = 2x\r \n" ); document.write( "\n" ); document.write( "=> By Pythagoras theorem in right angled triangle ABD\r \n" ); document.write( "\n" ); document.write( "AB2 + AD2 = BD2 \n" ); document.write( "(3x)^2 + (2x)^2 = (26)^2 \n" ); document.write( "9x^2 + 4x^2 = 676 \n" ); document.write( "x^2 = 676/13 \n" ); document.write( "x^2 = 52 \n" ); document.write( "x = 2 sqrt13 cm \n" ); document.write( "Thus, AB = 3x => 3 × 2 sqrt13 \n" ); document.write( "AB = 6 sqrt13 \n" ); document.write( "AD = 2x => 2 × 2 sqrt13 \n" ); document.write( "AD = 4 sqrt13\r \n" ); document.write( "\n" ); document.write( "Now Area of rectangle ABCD = AB × AD (length × breadth) \n" ); document.write( "i.e. 6 sqrt13 × 4 sqrt13 \n" ); document.write( "=> 24 × 13 \n" ); document.write( "=> 312 cm^2\r \n" ); document.write( "\n" ); document.write( "And Perimeter of the rectangle = 2 (AB + AD) [2(length + breadth)] \n" ); document.write( "=> 2 (6 sqrt13 + 4 sqrt13) \n" ); document.write( "=> 2 × 10 sqrt13 \n" ); document.write( "=> 20 sqrt13 cm \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " |