document.write( "Question 720171: A plane leaves the airport flying at 180 mph with a heading of 70 degrees. One hour later a second airpirt flying at 220 mph leaves the same airport with a heading of 345 degrees. How far apart are the airplanes at 1.5 hours after the first airplane leaves the airport? \n" ); document.write( "
Algebra.Com's Answer #441700 by ankor@dixie-net.com(22740)\"\" \"About 
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A plane leaves the airport flying at 180 mph with a heading of 70 degrees.
\n" ); document.write( " One hour later a second airplane flying at 220 mph leaves the same airport with a heading of 345 degrees.
\n" ); document.write( " How far apart are the airplanes at 1.5 hours after the first airplane leaves the airport?
\n" ); document.write( ":
\n" ); document.write( "The angle between the two aircraft (360-345) + 70 = 85 degrees
\n" ); document.write( ":
\n" ); document.write( "We can use the law of cosines here: a^2 = b^2 + c^2 - 2(b*c)cos(A)
\n" ); document.write( "Where
\n" ); document.write( "a = the distance apart after 1.5 hrs
\n" ); document.write( "b = 1.5(180) = 270 mi from the airport at this time
\n" ); document.write( "c = .5(220) = 110 mi from the airport at this time (left one hr later)
\n" ); document.write( "A = 85 degrees
\n" ); document.write( ";
\n" ); document.write( "a^2 = 270^2 + 110^2 - 2(270*110)*cos(85)
\n" ); document.write( "I'll let you do the math here, I got about 282.5 mi \n" ); document.write( "
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