Drawing a Line

I am trying to make a basic shape drawing utility on my prog.

Currently it's for darwing a triangle.

The user puts in the 3 sides(lengths) and they are drawn on a form.

All I have done so far is Drawn 3 lines on a form and match there length labels to the text input from the user. To adjust the lengths of the lines I assume I need to work off some kind of scale.
Right now I have this for side A:

Line1.y1 = txtSideA.text
line1.y2 = txtSideA.text

obviously this is no good

Any tips? Ideas on a scale?

Thanks Much!

First, you need a Base point for your triangle. Lets just
say it is 100, 100. Ok, now, lets assume that your sides
are 1, 1, and 1. We will multiply each by 100, so that it
would show up in VB. Now, what you need to do, is
plot two of the lines from 100, 100, so that their end
points are <length #3> apart. This is a real pain in the
arse. The method I would use (probably isnt very
good), involves plotting one line, then something like
this:

Code:

---

for i = 0 to 359
  if FIGetDist(line1.x2, line1.y2, 100 + line2length * cos(i * 3.14159), 100 + line2length * sin(i * 3.14159)) = line3length then
    line2.x2 = 100 + line2legth * cos(i)
    line2.y2 = 100 + line2legth * sin(i)
    exit for
end if
next i

---

in that code, line#legth is the legth of the line, FIGetDist
is a Distance between 2 points function, the 100 +
line#lenght * cos() is the X coordinate (the 100 is the X
coordinate of the start point), the 100 + line#legth * sin
() is the Y coordinate (again, the 100 is the Y coordinate
of the start point). That should help you out, i think.

Id also like to mention that that code wont cut and
paste. FIGetDist should return a single, and, in the
case of point distances, you will almost NEVER come out
with a whole number. You will have to modify it so that
it can be +- some amount of the line (say 5 twips).

Z.

The analytical solution:

Code:

---

  /|\
c/ |h\b
/  |  \
_d__d-a_
  a

---

h=sqr(c²+d²)=sqr(b²+(d-a)²)
c²+d²=b²+(d-a)²
c²+d²=b²+d²-2da+a²
d=(a²+b²-c²)/(2a)
h=sqr(c²-d²)

if you position your a-line, the base of your triangle, horizontal with the c-d corner in origo, you will have your c-b corner in x=d and y=h. The third corner will be in y=0 and x=a

set scalemode to User and change the scale properties so that you can place your triangle where you want, you could also scale and add offsets to the corner coordinates too if you want.

place all lines with respective coordinate 1 and 2 in the given coordinates to form your triangle.