Posted by yfaridi1 on .
Hello! I'm working on a lesson plan on the Sum of the Angles of a Polygon. I know the whole process involves finding how many triangles there are (#of sides minus 2) and then multiplying by 180degrees. But my focus on this lesson plan is on 5th grade students. How much detail can I really go into? What is the best way to introduce/open this lesson and what sort of activities would be age appropriate?
I don't need someone to do the plan for me, I just need some ideas! Im trying to create a nice lesson plan while keeping the age of the students in mind.
Thank you!

Education 
bobpursley,
I think I would do it with manipulatives at that grade.
Make a number of polygons from poster board start with triangle and end with an octogon. Then cut out triangles to fit into each polygon as "pizza" pieces. Let the kids measure the angles, add them up, and inductively predict each size of polygon the sum of internal angles.