document.write( "Question 297859: Hello,\r
\n" ); document.write( "\n" ); document.write( "I have 4 points given to me and I have to prove algebraically whether the figure is a kite. I can't just plot the points. How would I go about doing that?
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Algebra.Com's Answer #214423 by Fombitz(32388)\"\" \"About 
You can put this solution on YOUR website!
Given 4 points, divide them into two sets.
\n" ); document.write( "One set is the lengthwise component on the kite (line AB below).
\n" ); document.write( "The other set is the transverse (sideways) component of the kite (line CD).
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\n" ); document.write( "Calculate the eqaution of the line using the slope and the point-slope form of a line for the length wise component.
\n" ); document.write( "\"y-ya=m1%28x-xa%29\"
\n" ); document.write( " \"m1=%28yb-ya%29%2F%28xb-xa%29\"
\n" ); document.write( "Then convert to slope-intercept form
\n" ); document.write( "\"y=m1%2Ax%2Bb1\"
\n" ); document.write( "Do the same for the transverse component to get its equation,
\n" ); document.write( "\"y=m2%2Ax%2Bb2\"
\n" ); document.write( "If it's a kite, the lines will be perpendicular and the relationship between the two slopes will be,
\n" ); document.write( "\"m1%2Am2=-1\"
\n" ); document.write( "If that's not the case, then stop there. It's not a kite.
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\n" ); document.write( "If it is true then find the intersection point, I, between the two lines.
\n" ); document.write( "Solve the system of equations.
\n" ); document.write( "\"y=m1%2Ax%2Bb1\"
\n" ); document.write( "\"y=m2%2Ax%2Bb2\"
\n" ); document.write( "Since they both equal y, set them equal to each other.
\n" ); document.write( "\"m1%2Axi%2Bb1=m1%2Axi%2Bb2\"
\n" ); document.write( "Solve for x.
\n" ); document.write( "Then solve for y using either equation.
\n" ); document.write( "Now you have the point of intersection (xi,yi) of the two components of the kite.
\n" ); document.write( "If it's a kite, the distance from the intersection point (xi,yi) to the ends of the transverse components (C and D) must be identical.
\n" ); document.write( "\"Dci=Ddi\"
\n" ); document.write( "\"Dci%5E2=Ddi%5E2\"
\n" ); document.write( "\"%28xc-xi%29%5E2%2B%28yc-yi%29%5E2=%28xd-xi%29%5E2%2B%28yd-yi%29%5E2\"
\n" ); document.write( "If that's the case, then you've proven that the points form a kite.
\n" ); document.write( "If it's not true, then you don't have a kite.
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