Check whether students draw the correct function in Sketch and give immediate feedback.
It looks like this example references a graph that doesn’t exist – instead of a graph, there are some images. Is there a correct version of this example? If anyone knows of one, please direct me to it! Thank you.
I think this example does work, you just need to use the entirety of the sketch screen. Here’s some feedback I got from the first screen:
Thank you!! Now I see that I do have to use the entirety of the sketch screen… Something I need to make clear to my students when I use this feature (or, figure out how to put in a warning or feedback for students who do not use the complete sketch screen.
Again, thank you tenfold. I’ll now start messing around with this CL.
A.
It was also made with some pretty old tech. Maybe @sergeballif can give us an updated version?
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Here’s an updated version that is less complicated and more helpful.
@Jay @Alison_Signorotti Sketch Feedback Example Updated • Activity Builder by Desmos
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So, I thought I was being clever by randomizing things and adding some correctness checking to a slide that @sergeballif created and shared with me. Then I thought I was being clever by summarizing student results, and providing students with an overall grade / percent correct on screen 16. And I checked it – ran a class, enrolled in the class, and everything seemed to work.
But when more than one student is enrolled in the activity, the correctness checking on screen 16, and the feedback in the table on screen 16, stops working for any screen with a sketch.
I’m guessing the problem has something to do with the hidden CL behind the sketch checking. If there’s any way to fix it, I’d appreciate help, otherwise I’ll just delete that information from screen 16 and not assign a percent grade.
Here is the activity:
Thanks to all in this community.
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Super cool! Great job building feedback into the activity. I’m passing this along to my daughter’s teacher. 
I came across this post when I was trying to see if there was a way to check whether students plotted points correctly on a sketch. I tried to understand the coding and see how I could apply it to my assignment, but I am only a beginner on here and only really know basics… any thoughts? I appreciate any help and thank you in advance!
Validating points in a sketch is actually trickier. Using an image of a graph as a sketch background further muddies the waters, and you’d be better off with an Editable Graph background, IF you ultimately decided to go the route of a sketch.
Honestly, I’d opt to use something more like the draggable points in Screen 2 in @Alison_Signorotti 's activity to plot points.
Thanks for the tip. I’ll check it out!
If you want to use sketch, this is an example of how it could work. You can just replace the target points in the graph with what you need. plotting points check • Activity Builder by Desmos
I didn’t realize there was .pointXValues! I was thinking of ways to use xValuesAt( ).
@Daniel_Wekselgreene always on point! Pun intended.
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Thanks so much! This is exactly what I was looking for!
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This may be too much, but I figured I’d ask if it is somehow possible. Would there be a way to create a self-check to see if the students mark the corresponding parts of triangles congruent? Right now I just check each student as they finish myself; but I was thinking if putting the image into a coordinate plane and having images of the marks moved to specific points on the coordinate plane would be something that is possible? Or if it just wouldn’t be worth the hassle… anyone have thoughts?
This was a bit complicated but I gave it a shot. I made 2 templates (one with a shared side and one with 2 separate triangles) that you can hopefully modify without too much trouble. I made it so that sides are clickable, and each click cycles through 0 - 3 marks. When all sides are matching it will indicate correct. If you make new problems, try to keep the dimensions of the grid square, otherwise the marks will be kind of at an angle instead of perpendicular. Let me know if you have questions about how it works or how to modify it.
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This is awesome! I was able to recreate another one without any trouble. You gave a super easy explanation as to what I had to chance in order to make my own. It will take me a while to decipher all that you did and try to understand it. Based on the amount of work it took to make markings on the sides, I imagine making angle markings would be way more difficult… Thank you so much for your hard work in helping me get my vision to the assignment!
Hah, I was so focused on the marks I forgot about the angles. Well, I’m not especially great at trig 
so I added in arcs as a set of points that I then used ray casting to filter to only being inside the triangle… in other words it is taking a lot of processing power for something that could be more easily done with some good trig work. Give the second slide a try, and see if it works for you, but note that it may feel a bit sluggish when clicking on the dots.
If you have time to help with the trig calculations, then I could change the slide to be more responsive. Essentially, the problem is that, if you want to generalize, you would need to figure out two things for each arc area. One, you need the measure of the angle between the two line segments. Two, you would need to calculate the starting angle for the arc, which is based on the slope of the line segment you are starting from. You also have to account for the possibility of vertical lines, which can probably be handled by treating it as a slanted line with a really large slope.
I started doing this and made progress, but was having trouble getting it just right, so I threw in the towel and went with the other method.
I just wanted again to thank you for even taking the time to help me with this! I used the side congruence marks with my students today and it worked amazing!
I see what you mean about it being a bit sluggish, but besides that it’s awesome.
I haven’t brushed up on my trig in a while either but its probably time. Honestly, I am still working on understanding the programing from the angle marks (I am very low level with coding, but eager to learn); it feels like learning a new language to me. I haven’t used the graph option much yet, so I don’t even really know its full capability.
No problem, I enjoy the challenge of figuring this out! I went back and reviewed how vectors work and realized I could use that to solve the problem better than using the slopes of the lines. I added in a slide 3 using this method that works a lot better. I can go in and make a template for a shared side problem later. I was also thinking that I could add in calculations to generate the second triangle as a rotation/reflection/translation of the first, so it would be easier to make problems, as you would just create the first triangle, decide on the transformation you want, and then the coordinates of the second triangle would be already set.