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finding third coordinate

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koolelectrical

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Jun 9, 2009, 7:43:31 AM6/9/09
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I wanna know that how can i find third coordinate of right angled
triangle when i know two coordinates?

Jordan Hallin

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Jun 10, 2009, 4:45:26 PM6/10/09
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i have no idea... but you have to see this math rap i've found.
they mention trig ratios and there's a really funny binary solo.

http://www.youtube.com/watch?v=LkDhJsQA5_0

Greg Pack

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Jun 11, 2009, 9:21:55 AM6/11/09
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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 mid-point 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 point-slope 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.

Kirby Urner

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Jun 11, 2009, 9:21:48 AM6/11/09
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> I wanna know that how can i find third coordinate of
> right angled triangle when i know two coordinates?

Make a drawing or design maybe. Pythagoras is on your side
(your answer should confirm his theorem).

The importance of drawing in engineering is well expressed
by this MIT guy (poking around recommended):

http://www.opensourceteaching.org/participatingleaders/adrianbejan.html

You'll actually find some mathematicians who discount the
importance of drawings or visualizations of any kind.
Be on your guard!

Kirby

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