|
|
Available Now
Search
Contact
Feedback:
Send an e-mail with your
comments about this program (or anything else).
Help support DFF
If you benefit from the website, in terms of
knowledge, entertainment value, or something otherwise useful,
consider making a donation via PayPal to help defray the
costs. (No PayPal account necessary to donate via credit
card.) Transaction is secure.
|
| |
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
coordinates (0,0).
1. L22 = s2 + a2
(Pythagoras)
2. L32 = (L1-s)2 + a2
(Pythagoras)
3. L22 - s2 = L32 -(L1- s)2
(Identity - solve 1 & 2 for a2)
4. L22 - s2 = L32 - L12 + 2*L1*s - s2
(Expand 3.)
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
|
