Test output with toString() method
Triangle: "null"
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Edge("e1") connects nodes (n3, n1)
Edge("e2") connects nodes (n1, n2)
Edge("e3") connects nodes (n2, n3)
Node("n3") is at (3.0,0.0)
Node("n1") is at (3.0,4.0)
Node("n2") is at (0.0,0.0)
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Perimeter = 12.0
Area      = 6.0

Test pointInsideTriangle() method ...
*** Point (1,1) is INSIDE triangle
*** Point (3,1) is INSIDE triangle
*** Point ( 3.5, 1) is OUTSIDE triangle
*** Point (-3,1) is OUTSIDE triangle