Lesson Planning  


Lesson Planning 101 2. Area of Triangles
Dad: Do you need any help with your homework? Kid: No, I just have to study for my math test tomorrow. Dad: Well, maybe I can help? I was pretty good at math when I was in school. Kid: Sure. Dad: What is your test on anyway? Kid: It is on area of triangles, rectangles and parallelograms. Dad: Ok, all you have to do is memorize the formulas then. For a rectangle it is Length x Width, for a square it is Length x Width, for a parallelogram it is Base x Height and for a triangle it is one half Base x Height. Kid: Well, that’s a lot of formulas to remember. Did you know that all parallelograms are made up of two triangles that are the same? (kid demonstrates two triangles make a parallelogram) Dad: Well, that is interesting isn’t it? Kid: Yeah, so that’s why a triangle’s area is HALF Base x Height! Kid: Yes! And did you also know that all parallelograms can be turned into rectangles? Dad: Really? Show me how? Kid: Well, if you go to one corner on the bottom and draw a height line to the opposite side, it makes a small triangle that if you cut it off, it fits like a puzzle onto the other side to make a rectangle. Dad: Well what do you know!!! Kid: And since the area of a rectangle is Length x Width, it’s really the same as Base x Height. Dad: Now that is interesting. Kid: So, really, I only need to remember Length x Width, the rest of these shapes is using that formula to find area. Dad: You’re so smart! Kid: And, so now I am done studying and I’m going out to play! Song Who’s to say... you need to memorize... triangles, aren’t as difficult All you have to do is break it dowwwn.... So we have, length times width as area notice that, two triangles make up 

