Innovative
Classroom

Center Focus

Discovering the Area of Triangles

  1. You will need Geoboards and rubberbands for this activity.
  2. Have students make any triangle they wish on the Geoboard, keeping one side parallel to the side of the Geoboard. This side will be called the Base.
  3. Students will then find the area of that triangle. The area is found assuming the following: The smallest square on the board equals one unit of area, and the side of that square is one unit of length.
  4. Have students do this for at least four other triangles, recording their data as they go.
  5. Ask students if they can find a pattern and devise a formula that will always work for any triangle. The point of this exercise is to see if the students can come up with the formula for the area of triangles, which is
    A=(1/2)x(base)x(height).
  6. If you want to give them a hint in finding the formula, tell students to make two of the same triangles and form them into a parallelogram.
  7. You may want to have your kids use this Geoboard pattern to show how they found the area.

More Center Focus Ideas

Base10 Blocks
Write the Words
Picture Poems
Hackey Sack
Create an Instrument
Bumper Stickers
Sand Separation
Word Association
Broken Ruler
Matching Animals To Their Names
Bring Your Own Tale
Election 2000
Grateful for Acrostic
Discovering the Area of Triangles
How Much is 2000, Anyway?
Rhyming Match
Seasons
Guided by the Stars
The Medal Winners
Discover Music
Sand Painting
Egg Weight
Where Is This?
Personal vs. Country Pride
Celsius versus Fahrenheit
The Real Reason
How Far is Sydney?
Volume Conversions
Columbus Portraits
All Kinds of Genres
Walk a Mile in Their Boots
Toothpick Sculptures
Paint by Title
Irish Mobiles
European vs. Taino
Person, Place, or Thing?
Original Nature Tales
All About Easter
Haikon Mosaics
Halloween Word Search
Money Del Mundo
Spaghetti vs. Macaroni
Current Happenings in Science
What Do I Want to Know?
Alphabetizing Mania!
Jacks
Traditional Pumpkin Pie
Compare Hair
What’s Your Valentine Worth?
Millennium Inventions