document.write( "Question 927493: Two sides of a triangle measure 80 cm and 64 cm. The area of the triangle is 2,262 cm. Find the third side. \n" ); document.write( "
Algebra.Com's Answer #563034 by Alan3354(69443) You can put this solution on YOUR website! Two sides of a triangle measure 80 cm and 64 cm. The area of the triangle is 2,262 cm [sic] it's sq cm. Find the third side. \n" ); document.write( "============ \n" ); document.write( "Area = b*h/2 \n" ); document.write( "b = 80 \n" ); document.write( "A = angle between the given sides \n" ); document.write( "h = 64*sin(A) \n" ); document.write( "2262 = 80*64*sin(A)/2 = 2560*sin(A) \n" ); document.write( "sin(A) = 2262/2560 =~ 0.883594 \n" ); document.write( "A =~ 62.1 degs \n" ); document.write( "---- \n" ); document.write( "c = 3rd side \n" ); document.write( "c^2 = a^2 + b^2 - 2abcos(A) \n" ); document.write( "c^2 = 80^2 + 64^2 - 2*80*64*cos(62.1) \n" ); document.write( "c^2 = 6400 + 4096 - 10240*0.468254 = ~5701 \n" ); document.write( "c = 75.5 \n" ); document.write( "================== \n" ); document.write( "Check using Heron's Law \n" ); document.write( "s = (80+64+75.5)/2 = 109.75 \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "Area = 2261.89 \n" ); document.write( "=========================== \n" ); document.write( "It's surprising, I've been doing this stuff for 55 years or so, and never seen a problem like this one. \n" ); document.write( " |