Decomposing Polygons

Area of Composite Figures

G06.U05

Georgia Department of Education Dr. John D. Barge, State School Superintendent July 2013

All Rights Reserved Decomposing Polygons - 1

Pre-Assessment Task DirectionsSpend 15 minutes working individually on this task.

Read through the task and try to answer it as carefully as you can.

Show all your work so that I can understand your reasoning.

Don’t worry if you can’t complete everything. There will be a lesson that should help you understand these concepts better.

Your goal is to be able to confidently answer questions similar to these by the end of the next lesson.

G06.U07

Georgia Department of Education Dr. John D. Barge, State School Superintendent July 2013

All Rights Reserved Graphing on the Coordinate

Plane 2

Collaborative Introduction1) Find the value of x, y, and z in 2. Find the area of the polygon

the polygon below. below. (Show all work)

G06.U05

Georgia Department of Education Dr. John D. Barge, State School Superintendent July 2013

All Rights Reserved Decomposing Polygons - 3

Decomposing Polygons1. You have been grouped into pairs.

2. You will be given a set of task cards.

3. You will need to cut the task cards apart.

4. Calculate the area of the polygon on each task card.

5. On a poster, glue your task cards in order, from least area to greatest area.

6. Below each task card, neatly write the area and an explanation of how you arrived at your answer.

G06.U05

Georgia Department of Education Dr. John D. Barge, State School Superintendent July 2013

All Rights Reserved Decomposing Polygons - 4

Whole-Class Plenary Discussion

How did you determine the area for each figure?

For each figure, have students explain where appropriate breaks could be made. Have students explain.

Is there more than one appropriate place for a break? Have students prove their reasoning.

What are some mistakes that you think others could easily make? How could they avoid making those mistakes?

If a new student were to join our class tomorrow, what helpful hints could you give them so they will be successful in solving these problems?

G06.U05

Georgia Department of Education Dr. John D. Barge, State School Superintendent July 2013

All Rights Reserved Decomposing Polygons - 5