document.write( "Question 1200431: A boy cycles 8km on a bearing of 060°.
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document.write( "How far is the boy North of his starting
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document.write( "point? Give your answer to 2 s.f. \n" );
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Algebra.Com's Answer #834556 by math_tutor2020(3816)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Start facing directly north. \n" ); document.write( "Then turn 60 degrees toward the east (i.e. to the right). \n" ); document.write( "This will align you with the bearing 060° \n" ); document.write( "This is in the northeast quadrant.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Compass Rose: \n" ); document.write( " ![]() \n" ); document.write( "Image courtesy of Wikipedia. \n" ); document.write( "https://en.wikipedia.org/wiki/File:Compass_rose.png\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "This is what your rough sketch of the diagram should look like \n" ); document.write( " \n" ); document.write( "The boy starts at point P and moves to point Q. \n" ); document.write( "Note that 60+30 = 90.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let's erase the vertical line and erase the \"60 degree\" label. \n" ); document.write( "I'll add in a vertical line from Q to drop down to the horizontal line. \n" ); document.write( "It has length x to represent how far north Q is compared to P. \n" ); document.write( " \n" ); document.write( "The goal is to have a right triangle, so we can use a trig ratio to determine x.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sin(angle) = opposite/hypotenuse \n" ); document.write( "sin(30) = x/8 \n" ); document.write( "x = 8*sin(30) \n" ); document.write( "x = 8*0.5 \n" ); document.write( "x = 4 \n" ); document.write( "This value is exact. \n" ); document.write( "Make sure your calculator is in degree mode.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer: 4 km \n" ); document.write( " \n" ); document.write( " |