The Journal of Online Mathematics and Its Applications, Volume 6 (2006)
High End Video Conferencing in a Bridge-building/Mathematics Activity, Gerald Maring, et al.

Bridge Dialog: Calculate the Area of a Trapezoid


Cyber tutor: This is what we’re going to do. This is a trapezoid and more than likely our bridge design will include a trapezoid somewhere. So, at the end of our project we are going to calculate the area of a trapezoid. This is going to be our pre-test and when we finish the bridge project we’ll do this kind of a problem again as our post-test and we can say “Hey! You learned something.” Ok. That’s the goal. So, right now don’t worry about if you have the right answer or not. Do your best to try to figure it out on you own and then forget about it.

Kevin: I haven’t done this in like two years.

Kim: I’m looking at it and all I see are a bunch of numbers and a rectangular thingy that’s cut off at the sides. That’s all I see.

Cyber tutor: OK. So, the name of this is a trapezoid and what I want you to try and figure out is the perimeter…(she writes the term perimeter on the whiteboard)…

Kevin: Which is length times width.

Cyber tutor: …and the area (she writes the term area on board)

Kim: (to Kevin) Now when you say, length times width, would you like add the two 6’s together or what

Kevin: length times width (pointing at screen)

Kim: Yeah, but . . . you’re confusing me. Don’t do that. See, I get the length times width thing, what I don’t get is… How would you times it? Like would you put the two 6’s together? Would you add the 12 to the 16? I’m just seeing a whole bunch of numbers. I mean it doesn’t mean anything to me. I’m being honest here.

Cyber tutor: I am very grateful that you are being honest because the questions that you ask and that sort of thing, they help me, help us know what we can help you with. So we can help you do this that then when we are done with the project, you will be a wiz at doing this kind-of thing. So for right now, I want you to make your best guess. And then when you have your best guess down on paper we’ll work through it together. OK? … And don’t feel like I am going to jump all over you if you’re wrong because I don’t care if you are wrong or right. I just want to know what you know how to do and what you need help with.

Kim: I’m telling you right now that I going to be wrong because… I don’t know…

Kevin: That was a long time ago… I know you gotta times something…

{15 seconds pass}

Kevin: Don’t you just times 16 times 6 times 12 times 6… no dangit.

Cyber tutor: I’m not going to give you any hints, [because] this is a pre-test.

Kim: He’s mumbling things and I’m like… ha ha.

Cyber tutor: We’ll work on it. We’ll work on it. At least try to get something on paper on how you think you might solve this, Kim and then um we’ll go from there.

Kim: You’re funny; you’re so funny.

Cyber tutor: Ok, I going to give you one more minute.

Kevin: That’s all you got.

Kim: That is all I have on my paper, man. Wait you have the same thing except that you have a bunch more on it.

Cyber tutor: All right, you have forty seconds… no pressure, though. I’m just saying we’re going to move on to the next thing.

Kim: Forty seconds and no pressure after that. Ooooh!.

Kevin: Just put your head down and draw like this . . . make sure that you do something…

Kim: I can make it look like that.

Kevin: Do it. Forty seconds…

Cyber tutor: You guys are so funny. You make me laugh.

Kim: Yeah, so does your math problem. It makes me laugh.

Cyber tutor: Ok . . . Time’s up. Now what I want you to do is hold your paper up…. we [need] a record since I don’t have your paper in front of me. I can’t see what you did and what you didn’t do. So, this is kind-of a record so we can look back at the [VCR] tape. All right, hold it up a little higher [so I can see it on my monitor]. There we go . . . . Hold it up in front of your face and I will zoom in on it. Good. Now Kim I am panning over to you.

Kim: I have a bunch of little flowers.

Cyber tutor: Ok. We got it. Beautiful. Let’s move on. Ok. Let’s do some fun stuff. Have you guys been thinking about the structure of our bridge?