SOLUTION: show that (-3, 1), (3, -1) and (1, 3) are the vertices of an isosceles triangle. find its area

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Question 885497: show that (-3, 1), (3, -1) and (1, 3) are the vertices of an isosceles triangle. find its area
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
A(-3, 1), B(3, -1) and C(1, 3)
any two sides must be equal
Find AB, BC,CA
L(AB) =
Distance between two points
x1 y1 x2 y2

-3 1 3 -1
d= sqrt%28%28y2-y1%29%5E2%2B%28x2-x1%29%5E2%29
d= sqrt%28%28%09%09-1%09-%091%09%29%5E2%09%2B%09%28%093%09-%09-3%09%29%5E2%09%29
d= sqrt%28%28%09%09-2%09%29%5E2%09%2B%09%28%096%09%29%5E2%09%29
d= sqrt%28%28%09%0940%09%29++%09%29
d= 6.32
L(BC)
Distance between two points
x1 y1 x2 y2

3 -1 1 3
d= sqrt%28%28y2-y1%29%5E2%2B%28x2-x1%29%5E2%29
d= sqrt%28%28%09%093%09-%09-1%09%29%5E2%09%2B%09%28%091%09-%093%09%29%5E2%09%29
d= sqrt%28%28%09%094%09%29%5E2%09%2B%09%28%09-2%09%29%5E2%09%29
d= sqrt%28%28%09%0920%09%29++%09%29
d= 4.47
l(CA)
Distance between two points
x1 y1 x2 y2

-3 1 1 3
d= sqrt%28%28y2-y1%29%5E2%2B%28x2-x1%29%5E2%29
d= sqrt%28%28%09%093%09-%091%09%29%5E2%09%2B%09%28%091%09-%09-3%09%29%5E2%09%29
d= sqrt%28%28%09%092%09%29%5E2%09%2B%09%28%094%09%29%5E2%09%29
d= sqrt%28%28%09%0920%09%29++%09%29
d= 4.47
CA=BC
so it is an isosceles triangle
m.ananth@hotmail.ca