SOLUTION: Show that the point (6,6),(2,3) and (4,7) are the vertices of a right angled triangle

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Question 1009174: Show that the point (6,6),(2,3) and (4,7) are the vertices of a right angled triangle
Found 2 solutions by jim_thompson5910, ikleyn:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Let

P = (6,6)
Q = (2,3)
R = (4,7)

Find the slope of segment PQ to get 3%2F4


Find the slope of segment PR to get -1%2F2


Find the slope of segment QR to get 2


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Multiply the slopes of PR and QR to get

(slope of PR)*(slope of QR) = (-1/2)*(2) = -1

Since the product of the two slopes is -1, this means that segment PR and segment QR are perpendicular. We have a right angle form at where the segments meet (at point R)

So we definitely have a right triangle.

Answer by ikleyn(52778) About Me  (Show Source):
You can put this solution on YOUR website!
.
Show that the point (6,6), (2,3) and (4,7) are the vertices of a right angled triangle.
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Calculate the three segments in the coordinate plane that are sides of the triangle.

For example, one segment, connecting the points (6,6) and (2,3), is (6-2,6-3) = (4,3).
Its length is sqrt%284%5E2+%2B+3%5E2%29 = sqrt%2825%29 = 5.

Two other segments are (2,-1) and (2,4).
Their lengths are sqrt%282%5E2+%2B+%28-1%29%5E2%29 = sqrt%285%29 and sqrt%282%5E2+%2B+4%5E2%29 = sqrt%2820%29.

Now notice that 5%5E2 = 25 and %28sqrt%285%29%29%5E2 + %28sqrt%2820%29%29%5E2 = 5 + 20 = 25.

It is just enough to state that the triangle is right-angled.
The point (4,7) is the vertex of the right angle.