The easiest way is to ignore the zeros. However, this can be done several different ways. It will depend on how the program is prompting the user for the values. You could input the values one at a time. You could input the values in a list. You could have a more complex input such as this program. You could even have an input with a triangle on the graphscreen, such as the one below. However, most will ignore the zeros.

Using Weregoose's triangle solver code, here is a quick triangle solver that I created:

Here is the code (which could probably be optimized):

```
ClrDraw //setup graphscreen
AxesOff
FnOff
ZStandard //friendly window
84→Xmin
⁻72→Ymin
ZInteger
Text(0,0,"TRIANGLE SOLVER
Line(20,⁻48,76,⁻48
Line(20,⁻48,48,⁻17
Line(76,⁻48,48,⁻17
Text(57,0,"2ND-EDIT | ENTER-SUBMIT
DelVar ADelVar BDelVar CDelVar DDelVar EDelVar F //sets all values to 0
1→G
Lbl 1
Repeat K=105 or K=45
Text(9,36,"A=",A //displays labels and values
Text(49,8,"B=",B
Text(49,66,"C=",C
Text(49,36,"a=",D
Text(27,68,"b=",E
Text(27,12,"c=",F
{9.32,27.08,49.04,49.32,49.62,27.64 //coordinates of cursor
Text(iPart(Ans(G)),ᴇ2fPart(Ans(G)),"► //draw the cursor
Repeat max(Ans={21,24,26,45,105
getKey→K
End
{9.32,27.08,49.0,49.32,49.62,27.64
Text(iPart(Ans(G)),ᴇ2fPart(Ans(G))," " //erase the cursor
G+(K=26)(G<6)-(K=24)(G>1→G //updates cursor variable
If K=21:Then //input value
Input sub("AcBaCb",G,1)+":",H
If G=1:H→A
If G=2:H→F
If G=3:H→B
If G=4:H→D
If G=5:H→C
If G=6:H→E
End
If K=45:Return //clear = quit
End
{A,B,C→L₂ //angles
{D,E,F→L₁ //sides
Degree //solver code
not(L₁)(L₂+not(L₂)(180-sum(L₂
max(L₁)sin(Ans)/sin(sum(Ans+min(L₁
If 2=sum(not(Ans
√(sum(L₁²)-prod(L₁+2not(L₁)cos(max(L₂
If min(L₁) or max(L₁ and L₂)≠sum(not(L₁
Then
Goto 0
End
For(X,⁻1,1,2
max(L₁not(L₂
Anscos(L₂)+X√(L₁²-Ans²sin(L₂)²
max(Ansnot(not(L₂
Lbl 0
L₁+Ansnot(L₁→X
If min(real(Ansnot(imag(Ans
Then
Ans→L₁ //sides
cos⁻¹(Ans/prod(Ans)(.5sum(Ans²)-Ans²→L₂ //angles
sum(.5ʟX
√(Ansprod(Ans-ʟX→I //area, but not displayed
End
End
L₁(1→D //stores updated values
L₁(2→E
L₁(3→F
L₂(1→A
L₂(2→B
L₂(3→C
Goto 1 //go back up to display values
```

Edit: Included comments. For easy copy and paste code, look at the first revision.

The GUI code takes 514 of the 786 bytes. The actual solver accounts for just over 200 bytes.