by Melody Bienfang

Geometry (8th Grade)

Plotting Points & Areas of Shapes

Melody Bienfang
To obtain a downloadable copy of the worksheet that accompanies this bulletin board, click on the button below.

TITLE: Activities on the Cartesian Plane

SUBJECT: Geometry

TOPIC: plotting points, finding area of shapes (grade 8)

INTERACTIVITY: In order to interact with the bulletin board, the student first has to take an index card and be able to plot the points indicated on the card. To do this, the student will take the number of flies needed and plot each one of the points on the card by tacking the fly to the bulletin board in the appropriate place. Then the student will take a rubber band from the labeled envelope and stretch it around the flies he just plotted to form a shape. Only when the student has interacted in this way will he be able to complete the accompanying worksheet.

DIRECTIONS FOR USE: To start, write the following formulas for the area of each shape: (square, triangle, rectangle, and trapezoid). Next, pick an index card from the envelope labeled 'Points to Plot.' Then take as many files from the 'Flies'envelope as necessary and tack them to the indicated points on the card. Once you have plotted all the points on the card, take a rubber band and stretch it around the flies to form a shape.

Then begin filling in the answers below for the appropriate color card. You must show your work for how you computed the area. Each tick mark on the coordinate plane represents one unit, so your units will be units_. Once you have completed the information for that colored card, carefully remove the rubber band and the flies. Then pick a different colored card and repeat the process. You will repeat the process for all five different colored cards, thus completing the activity. Remember, distance is never negative. And don't forget to answer the very last question at the end!

TIME: 20 minutes

SPECIAL CONSTRUCTION: I used thumb tacks for the flies and rubber bands to make the shapes.

CREDIT: The students will get a maximum of 10 bonus points on their next test for completing the bulletin board activity.

Melody Bienfang
Fall 2007