This is a discovery activity. Students will discover by checking the area of several triangles having different shapes that because the altitudes are the same the areas are the same. MaTIlda (a little spider) helps the students. She and her family members live on the railroad tracks which are, of course, parallel. MaTIlda weaves triangular webs to help feed her parents and her children TIna, MatTI, DotTI, and TIm.
Before the Activity
The teacher should download the spider.tns file from the activity exchange and transfer it to each student handheld.
During the Activity
Let students explore using the TNS file.
After the Activity
A possible extension is to have students measure the perimeter of each triangle and compare those lengths. Which child is MaTIlda spending more on, if you consider the amount of "silk" (perimeter of each initial triangle) that she has to produce to build each web as currency?