Triangle Solver and realistic drawing of a solved triangle

[mcjtom]

Built in Triangle Solver App is great: this is so universally useful and yet relatively difficult to solve that I think all calculators should have it as a built-in function/solver - without having to programme it.

Two ideas for improvement are:

- reporting area and perimeter
- updating the triangle image so that it approximately reflects the solution

I would find the latter improvement invaluable in explaining to students why sometimes there are two solutions to a triangle, sometimes none... Also, the provided triangle image is useful for entering known elements, but it's quite confusing when the solved triangle is not even close to the shape of the static triangle image shown - I have to cover the triangle drawing when displaying it in class not to confuse the students...

[eried]

(08-06-2014 10:42 AM)mcjtom Wrote:  Built in Triangle Solver App is great: this is so universally useful and yet relatively difficult to solve that I think all calculators should have it as a built-in function/solver - without having to programme it.

Two ideas for improvement are:

- reporting area and perimeter
- updating the triangle image so that it approximately reflects the solution

I would find the latter improvement invaluable in explaining to students why sometimes there are two solutions to a triangle, sometimes none... Also, the provided triangle image is useful for entering known elements, but it's quite confusing when the solved triangle is not even close to the shape of the static triangle image shown - I have to cover on the class LCD image not to confuse the students...

Hey, I've seen that you have lots of suggestions from another point of the prism (besides majority here, who basically liked the 50g and wanted a *newer* 50g), maybe it makes sense to write your suggestions here: http://www.tricider.com/brainstorming/2eKfifdjarx (just so they aren't lost if nobody answers them).

Nothing official but just a way to keep them a bit 'organized'.

[resolved]

Great suggestions that I would also like to see implemented.

also for pedagogical reasons, it would be nice to have a tab "How Solved" which would switch to a new screen showing how the solution was derived.

[mcjtom]

Here is one more suggestion (perhaps it's already possible, but I don't know how to get to it):

The results of a solved triangle (3 sides and 3 angles) can be already copied and pasted to the stack or spreadsheet, but only one by one.

I thought it would be helpful if they could be exported (copied) in bulk: for example as a list of all of them or two lists - one with 3 sides, the other with 3 angles. List can be pasted to spreadsheet range already and to the stack and operated on (if the list could be disassembled to stack somehow, that would be even more useful).

Cheers!

[mcjtom]

This is total nitpicking that doesn't make much difference, but I'll mention it anyway: I was showing the official promo video on HP Prime to others, and there is a short clip on Triangle Solver previous reincarnation, which looks almost exactly like the present one but the angles are not A, B,C (like vertices) but Greek symbols for alpha, beta and delta (why not gamma?). The sides were named A,B,C....

   

It may be just me, but in present App I keep confusing A,B,C with a,b,c not knowing which untitled column of entry boxes contains side length entries and which angles (yes, there is a prompt...). With Greek symbols I would probably know right away that these are angles, with the other 3 (either being a,b,c or A,B,C) being sides.

A side note is that, again it's probably me only, I've spent the last few days conditioning myself that A,B,C,... are reserved numerical Home view variables, while a,b,c,... are reserved CAS objects. I know that the triangle solver has nothing to do with it, but still...

Cheers!

[Angus]

I share your thoughts. In Europe angles are almost entirely labeled in greek letters.
It doesn't make much of a difference, yes. But if you expect confusion when using the solver changing the naming of the angles is a small change compared to an animated drawing.
If sides and angles are labled without ambiguity I would expect every student to be able to deal with different geometries... I see no need nor sense in adding additional comfort there.

edit: Think of astronomical dimensions - you could easily see a line if thinking of the triangle scaled correctly e.g.

[mcjtom]

Maybe at least something like this, if vertices labeled as capital letters are there to stay:

∠A,∠B,∠C...?

[Joe Horn]

(08-07-2014 04:04 AM)mcjtom Wrote:  Here is one more suggestion (perhaps it's already possible, but I don't know how to get to it):

The results of a solved triangle (3 sides and 3 angles) can be already copied and pasted to the stack or spreadsheet, but only one by one.

I thought it would be helpful if they could be exported (copied) in bulk: for example as a list of all of them or two lists - one with 3 sides, the other with 3 angles. List can be pasted to spreadsheet range already and to the stack and operated on (if the list could be disassembled to stack somehow, that would be even more useful).

Instead of copying and pasting one by one, I suggest using the app's own global variables: SideA, SideB, SideC, AngleA, AngleB, and AngleC. They're even available when the Triangle Solver is not the current app. They are all available in a few keystrokes: Vars [App], Triangle Solver (use the single shortcut key for it), 1, then 1 through 6. Just 4 keystrokes, plus one tap if the App tab isn't already selected. Copy, Home, Paste is even fewer keystrokes (if you don't count the Shifts), but then you only get one value.

[mcjtom]

Risking beating a dead horse, here are a few more issues I discovered with Triangle Solver App:

- the programme seems to be checking if the sum of angles>180deg, but not if it's less than that. Also, entered angles are not checked right away for 180deg equality (if all 3 are entered), instead a message to enter 'at leas one side' appears.

- the calculated elements of a triangle are highlighted, but this seems to be only an ornamental distinction from the entered values: if I'd like to experiment with how changing a value of one element changes the solution, I need to delete all the unneeded elements first by hand each time I adjust it.

- when a side is edited, the "sum of angles > 180deg" can appear even if the visible sum of angles is ok.

- Angles of 180deg are allowed; moreover, if a=0, b=0, c=0, "infinite solutions" is the result (whatever that means for a triangle...), but when a=0, b=0, c=5 there is a cryptic message that there are "no solutions given data" (but why?). Another exampel is a=0, b=0, c=0, A=5, B=5, C=5 which results in 'Infinite Solutions' - it's not a triangle, even out of many.

- "solution found" is displayed even after editing entries - it's easy to think that the new values entered, before pressing Solve, are the solution.

[Anderson Costa]

(08-09-2014 10:43 AM)mcjtom Wrote:  Risking beating a dead horse, here are a few more issues I discovered with Triangle Solver App:

- the programme seems to be checking if the sum of angles>180deg, but not if it's less than that. Also, entered angles are not checked right away for 180deg equality (if all 3 are entered), instead a message to enter 'at leas one side' appears.

- the calculated elements of a triangle are highlighted, but this seems to be only an ornamental distinction from the entered values: if I'd like to experiment with how changing a value of one element changes the solution, I need to delete all the unneeded elements first by hand each time I adjust it.

- when a side is edited, the "sum of angles > 180deg" can appear even if the visible sum of angles is ok.

- Angles of 180deg are allowed; moreover, if a=0, b=0, c=0, "infinite solutions" is the result (whatever that means for a triangle...), but when a=0, b=0, c=5 there is a cryptic message that there are "no solutions given data" (but why?). Another exampel is a=0, b=0, c=0, A=5, B=5, C=5 which results in 'Infinite Solutions' - it's not a triangle, even out of many.

- "solution found" is displayed even after editing entries - it's easy to think that the new values entered, before pressing Solve, are the solution.

The app only asks for 3 of 6 values....I have tested these bugs and I am doubtful about what is a triangle with this app... about 180 degree angles, if a=b=c=0, this result in a line, a case of degenerated triangle. The Triangle Solver must have a check of sum of angles measures to solve these bugs...

[patrice]

With Prime one can derive a new App from another.

Did one try to derive a new App from the Triangle solver and program your own Plot handling to draw a real looking triangle ?