As of October, 2016, Embarcadero is offering a free release
of Delphi (Delphi
10.1 Berlin Starter Edition ). There
are a few restrictions, but it is a welcome step toward making
more programmers aware of the joys of Delphi. They do say
"Offer may be withdrawn at any time", so don't delay if you want
to check it out. Please use the
link to let me know if the link stops working.
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Given three line segments, L1,L2,L3, construct a triangle if possible by defining
the coordinates of the three corners.
Here's the math to determine the coordinates of the third point if the line labeled L1 (and with length L1) is placed horizontally starting at
1. L22 = s2 + a2
2. L32 = (L1-s)2 + a2
3. L22 - s2 = L32 -(L1- s)2
(Identity - solve 1 & 2 for a2)
4. L22 - s2 = L32 - L12 + 2*L1*s - s2
5. s = ( L22 + L12 - L32) / (2*L1)
(Solve 4. for "s")
6. a = sqrt( L22 - s2 )
(Solve 1. for "a")
The program lets you view the effect of changing side lengths by drawing the
resulting triangle and displaying the (s, a) coordinate.
Running/Exploring the Program