document.write( "Question 1196022: On his way to room, Liza traveled 3 km North and
\n" ); document.write( "4 km West. What is the displacement made by Liza?
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #828688 by math_tutor2020(3817)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "Define these points
\n" ); document.write( "A = Liza's starting point
\n" ); document.write( "B = the point 3 km directly north of point A
\n" ); document.write( "C = the point 4 km directly west of point B, which is Liza's ending point\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The points form a right triangle. The 90 degree angle is at point B.
\n" ); document.write( "I recommend drawing out a quick sketch of this. It doesn't need to be perfect or to scale.
\n" ); document.write( "See the diagram at the bottom.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "We can use the pythagorean theorem to find the distance from A (Liza's starting point) to C (Liza's ending point).
\n" ); document.write( "All displacement cares about are these two points. Any stuff in the middle is ignored.
\n" ); document.write( "Think of displacement being the ultimate shortcut you can take when going from the beginning directly to the ending.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The right triangle has legs of a = 3 and b = 4
\n" ); document.write( "The unknown hypotenuse is c\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Let's apply the pythagorean theorem to solve for c.
\n" ); document.write( "\"a%5E2+%2B+b%5E2+=+c%5E2\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"c+=+sqrt%28a%5E2%2Bb%5E2%29\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"c+=+sqrt%283%5E2%2B4%5E2%29\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"c+=+sqrt%289%2B16%29\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"c+=+sqrt%2825%29\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"c+=+5\"
\n" ); document.write( "We have a 3-4-5 right triangle, which is perhaps the most famous of the many pythagorean triples.
\n" ); document.write( "To confirm this is correct, you could use a tool like GeoGebra as shown below
\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Therefore, the distance from A to C is 5 km.
\n" ); document.write( "This is the displacement.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Answer: 5 km
\n" ); document.write( "
\n" ); document.write( "
\n" );