Download The Greedy Triangle Lesson Plan

Amanda Herwig
Lesson Plan Using Literature
9/20/12
Burns, Marilyn. The Greedy Triangle. New York; Scholastic, Inc. 1994
The Greedy Triangle begins with an anthromorphized triangle who loves his shape. The
illustrations show the many different ways the triangle is seen in the world. Only, the
triangle does not stay happy as a triangle and gets a shapeshifter to turn him into a
quadrilateral. The book continues with examples of quadrilaterals until the triangle
continues to add shapes and angles to form new polygons. Eventually the shape is too
contorted to be of much use and turns back into a happy triangle.
Situating the Lesson:
This lesson is for first grade students. It will introduce the concept of shapes and show
basic shapes such as triangles and squares as well as get the children to think about more
complex polygons and their relationship in terms of sides and angles. The book will help
illustrate that there are more than one type of triangle and it is not wrong to draw
different shapes.
Methods of Inquiry:
Text analysis, basic rules of geometry.
Instructional Goals:
First graders will be able to identify and name basic shapes such as triangles and
quadrilaterals, and will be introduced to shapes with more sides, such as pentagon,
hexagon, heptagon, and octagon. The relationship between shapes will be established so
students will see how adding sides adds angles and creates a new shape, and how these
shapes can form each other.
Essential Questions:
Can you draw a triangle?
What does a square look like?
Do you see these shapes around us in everyday life?
What do you need for a triangle to become a quadrilateral?
State and/or Content Standards (indicate source):
1.G.1. Describe attributes and parts of two- and three-dimensional shapes (e.g., length of
sides and number of corners, edges, faces, and sides).
http://dcps.dc.gov/DCPS/In+the+Classroom/What+Students+Are+Learning/Learning+St
andards+for+Grades+Pre-K-8
Instructional Materials:
1. The book, The Greedy Triangle
2. Cutouts of right, equilateral, and isosceles triangles, square and rectangle, pentagon,
hexagon, heptagon, and octagon.
3. Powerpoint or pictures of a cut pie, door, pentagon shaped house, a stop sign, and other
images where you can see shapes in everyday objects.
4. Students will have paper and pencil at their desks/tables.
Set Induction:
“I want to read a fun book about a triangle. As I read, let’s think about what makes him
greedy and what shapes you see in the pictures. Then we’ll talk about if you’ve seen
these shapes before and what to call each shape.”
Procedures (Lesson Content/Skills/Teaching & Learning Strategies):
1. Introduce book and instruct students to take note of pictures and shapes, as well as
the names of the shapes.
2. After reading, talk about examples of the shapes illustrated in the book. Discuss
where you see these shapes everyday. Have pictures ready to show them a stop
sign is an octagon, a door is a rectangle, etc. Ask if students can identify shapes in
the classroom.
3. Introduce cutouts of different shaped triangles. Show the students an equilateral
triangle and ask them what shape it is. Show them a right triangle and ask what
shape this is. Note how as long as it has 3 sides and 3 angles, it is a triangle.
Continue with square and rectangle and have them point out the differences is
side lengths.
4. Ask what a triangle needs in order to become a quadrilateral. How many sides
would you add to make a square a pentagon?
5. Encourage students to look around and note how everything has a shape. Be
prepared for questions about circles or irregular shapes.
Assessment/Closure:
Ask students to draw a triangle, square, and rectangle on their own paper. Ask them to
write how many sides/angles a triangle has, how many sides/angles a square has. Provide
cutouts of the shape and see if they can give an example of where one can find that shape.
Take note of each student’s comprehension, and plan to arrange a small group lesson the
next day if they need more help to identify shapes.