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Re: finding third coordinate
Posted:
Jun 11, 2009 9:21 AM


Connect the points of the coordinates you are given and you have a segment that is either a hypotenuse or a leg of your right triangle. Now all you need is a third point. Easy. You can choose any point from one of three infinite sets of possibilities. One set is a circle and the other two are lines.
Suppose your segment is a hypotenuse. Find the midpoint and use it as the center of a circle through the endpoints. Every point on this circle can be the vertex of the right angle of your right triangle. Pick any point on the circle [except the endpoints]. There are an infinite number of third points you can use to find the coordinates. Use the standard equation of a circle with your midpoint center (h, k) and a radius half the length of your segment to show an equation for your locus of points.
Suppose your segment is a leg. Find the slope of your segment. Use the opposite of the slope's reciprocal to give you the slope of a line perpendicular to your leg. Now use the pointslope form of a linear equation to find the equation of the line through each endpoint of your [segment] leg. This line represents an infinite number of points that would work as your third point to form a right triangle. Repeat the process and you have another equation for another infinite set of possible third points.
Hope that helps.
 Original Message  From: "koolelectrical" <smamalik24@gmail.com> To: <geometryprecollege@moderators.isc.org>; <geometryprecollege@support1.mathforum.org> Sent: Tuesday, June 09, 2009 6:43 AM Subject: finding third coordinate
>I wanna know that how can i find third coordinate of right angled > triangle when i know two coordinates?



