Grade 4 Geometry Tiered Lesson
Dr. Denise LaFrance
Essential Question(s) and/or Goal including Rationale: The goal of this lesson is for
students to understand that triangles are made up of 3 angles either acute, right, and/or
obtuse. It is necessary for students to learn about angles and their placement in triangles in
order to understand more complicated concepts in geometry. In addition, students need to
be able to find examples in their environment to make the connection between math and
their everyday lives.
Essential Questions: What are the attributes of the three angles in their measurement?
What geometric shapes are formed when the angles are connected? Where can you find
these angles in your environment?
Formative Assessment: The formative assessment in this part of the lesson is observing
the students as they practice using the movable angles to identify the three angles within
the triangles. Students who struggle with this task will be given assistance.
Summative Assessment: Each tier has a different summative assessment. Each of the
following will be collected to determine whether the students met the objectives: Tier 1:
The student made books; Tier 2: The worksheet with the categories of angles found in the
classroom; Tier 3: The 3-circle Venn diagram.
MA Curriculum Frameworks:
4.G.1 Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular
and parallel lines. Identify these in two-dimensional figures.
4.MD.5 Recognize angles as geometric shapes that are formed wherever two rays share a
common endpoint, and understand concepts of angle measurement.
Connections Across the Curriculum: This lesson contains ELA connection through the
reading of The Greedy Triangle by Marilyn Burns and the writing in the various activities.
Objectives:
Given a movable angle, the students will be able to demonstrate and identify the location of
a right, acute, and obtuse angle within a triangle in 8 out of 10 opportunities.
Given geometric models, the students will be able to identify the name of the triangle and
the angles that make up that triangle in 8 out of 10 opportunities.
Given instruction on the attributes of the three angles, the students will be able to identify
the various degrees in each angle with 90% accuracy.
SPED 3400 Teaching Math to Students with and without Disabilities
Activator: 20 minutes
Materials: The Greedy Triangle by Marilyn Burns, triangle magnets, large movable angle,
small movable angles.

In a whole group on the rug, I will hold up a model of four triangles: an acute triangle,
an obtuse triangle, a right triangle and an equilateral triangle. I will ask the students
what they notice about them. How are they similar? How are they different? Why do
you think they are called triangles?

Next I will read the story, The Greedy Triangle by Marilyn Burns. During the reading,
I will stop and ask questions to the students and I will tell them to notice the angles
used in the various shapes in the book.
After the story, I will introduce three new geometric terms: right, acute, and obtuse
angles. I will explain the attributes of each angle: an acute angle is <90 degrees, and
right angle is 90 degrees, and obtuse is >90 degrees.
Using a movable angle made with construction paper and a brad, I will model for the
students how to move the angle along the vertices of the triangles. We will discuss
and identify the various angles found within the triangle.
Finally I will pass out movable angles to each student and they will come to the
whiteboard and practice identifying each angle within the triangles.
I will give directions for each of the stations below and the students will move back
to their seats to will complete the activities.




Adaptations: This lesson is differentiated to meet all student needs through a series of
tiered activities. Tier 1 is designed to help struggling students working slightly to
moderately below grade level. Tier 2 is designed to meet the needs of students who are on
grade level in math. Tier 3 is designed for students working above grade level in math.
SPED 3400 Teaching Math to Students with and without Disabilities
Procedure: 15 minutes
Tier 1 (low)
Objective:
By the end of the activity, the students will create a book and illustrate the three geometric
terms (acute, right, obtuse) with 80% accuracy.
Materials: Paper, pencil, stapler, colored pencils
Procedure:





I will work with the students in a small group at a kidney shaped table.
The models of the triangles will be brought over to the group along with the movable
angles. Each student will demonstrate the three angles using the movable angles.
Next each student will be given 2 sheets of paper and they will fold them in half to
make a book and I will secure the book by stapling the crease.
On each page the students will write the name of the angle and draw an illustration
of that term using colored pencils. The students will be encouraged to add a title to
the book on the front.
Finally I will give the students a blank sheet of paper and ask them to write their first
name in capital letters using their best handwriting. Next I will challenge them to
look at the letters in their name and find how many angles they can find.
Tier 2 (middle)
Objective:
By the end of this activity, the students will identify and find examples of the three angles
around the room with 90% accuracy.
Materials: Paper, pencil, alphabet strip on the wall, worksheet with 3 categories, classroom
environment
Procedure:


The students will be placed into pairs and work independently.
Each pair will be given a sheet of paper that is divided into 3 categories, one for each
geometric term (acute, right, obtuse).
SPED 3400 Teaching Math to Students with and without Disabilities


The student pairs will be given 10 minutes to find as many examples of each as they
can, and then draw a picture or a written description about it in the correct category
on the paper.
Finally, the students will be challenged to look at an alphabet strip hanging on the
wall and find a letter for each that contains an acute, right, and obtuse angle. The
students will write the letters on a piece of paper to share with the class.
Tier 3 (advanced)
Objectives:
Given a worksheet with illustrations of a an acute triangle, an obtuse triangle, a right
triangle and an equilateral triangle, the students will locate and trace the three angles using
colored pencils with 90% accuracy.
Given a 3-circle Venn diagram, the students will compare and contrast the attributes of the
four triangles explicitly using the three geometric terms (acute, right, obtuse) with 90%
accuracy.
Materials: Paper, pencil, 3-circle Venn diagram
Procedure:




The students will work in pairs and discuss the similarities and differences of the 4
triangles.
The students will be given a paper with illustrations of the four triangles, the
students will trace the acute, right, and obtuse angles using different colored pencils.
Next each pair will be given a 3-circle Venn diagram. They will choose 3 of the 4
triangles to compare and contrast the attributes of each.
Finally, the students will be challenged to create a four letter word ,written in capital
letters, that contains the largest number of angles. Each pair will write the word on a
piece of paper to share with the class.
Closure: 10 min.
The students will return to the rug and they will share their challenges of finding how many
angles in their name (tier1); finding 3 letters on the alphabet strip that contain an acute,
right, or obtuse angle (tier 2); and finding a 4 letter word with the most angles (tier 3).
SPED 3400 Teaching Math to Students with and without Disabilities