# Making a Polygon Disappear

Is it possible to make a polygon (defined in a graph component) appear and disappear by pressing a button or based on some other condition?

I can do this for a function or an ordered pair, (see the link) but I am wondering if it is possible for a polygon too, because it will not work in the same way?

Thanks!

It works similar to an ordered pair where you need to place the conditional inside the parentheses.

Wlhat is the best practice to compare a point to a point? I want a polygon to appear when a point is placed on another point. For example if point A_1 is moved to point A’s location then polygon appears. Slide 1 of this activity https://teacher.desmos.com/activitybuilder/custom/6019fb24c5d1dc4fc46f9f53… is where I’m trying to give students feedback. Do I need to parse out the x and y coordinate of each point?

Like this?

I thought since you are moving the points continuously (not snapping) it made sense to give how close the points were a range so the students wouldn’t need to get it exactly to see the triangle, so I used absolute value in the restrictions. Look at line # 12 on the graph of slide #1 and move the 45 degree point to show the triangle for 45 degrees. Also, I changed the points so A_1=(a_x,a_y) etc. which essentially makes the graph parse the coordinate for you by prompting you to add sliders; then you can refer to the x and y coordinates of each point individually.

I like it! Kevin’s idea of allowing students to be close but not directly in the point is good too. I’ll play with both. I didn’t know the calculator parses out the x and y.

This worked well. Thanks so much! I know just enough to be dangerous, but I’m learning more every chance I get to create. Cold day tomorrow so more progress going forward I hope.