Triangle Lesson

7/28/2019 Triangle Lesson

1/3

Kelly Collova

Dr. Bulgar

ELD 375

April 11, 2013

Triangles

Rationale

I am teaching this lesson so that students can learn how to describe a triangle by thelengths of its sides and by the size of its angles. It is important to understand the different

attributes of the triangles so that students learn the correct geometric names of the triangles.

CCSS.Math.Content.3.G.A.1 Understand that shapes in different categories (e.g.,

rhombuses, rectangles, and others) may share attributes (e.g., having four sides), and that the

shared attributes can define a larger category (e.g., quadrilaterals). Recognize rhombuses,rectangles, and squares as examples of quadrilaterals, and draw examples of quadrilaterals that

do not belong to any of these subcategories.

Objective

Students will be able to identify attributes of different triangles and classify the triangles

into groups according to their attributes (lengths of sides and size of angles).

By the end of this lesson, students will be able to distinguish the difference between an

equilateral triangle, isosceles triangle, scalene triangle, right triangle, acute triangle, and obtuse

triangle.

Lesson Progression

Grade: 3

1. Students will be instructed to clear off their desks.

2. Triangle blocks and triangle paper cut outs will be distributed to the students.

3. Teacher will ask students what they know about triangles.

4. Teacher will have students organize the triangle blocks and paper triangle cut outs into

groups according to the attributes of the triangles. Teacher will walk around the room and assist

students if needed.

5. After students organize triangles into groups, teacher will call on students to share

with the class how they grouped their set of triangles.

6. Teacher will then introduce the names and description of the triangles (equilateral,

isosceles, scalene, right, acute, obtuse) with a drawing of each that were given to the students.


2/3

Teacher will explain the classifications by sides and angles. Students will write the names and

definitions of the triangles in their math notebook.

7. Teacher will then have each table work together and group the triangles according to

their attributes and correctly name each group of triangles they made.

8. Table of students will present the groups to the teacher as teacher walks around.Teacher will have students explain their reasoning for each group.

9. Close: Teacher will call the students attention and have students review the namesand description of each triangle learned in the lesson. (or students will watch Envision video for

review)

Teacher will ask the class questions like:

What is the difference between an isosceles triangle and a scalene triangle? What is the difference between an equilateral triangle and an isosceles triangle? What are the names in which triangles are classified by their angles? How many angles of an obtuse triangle must be obtuse?

Other Considerations

The materials needed for this lesson are triangle blocks, paper cut outs of triangles,

student math notebook, and a Smart Board for Envision video.

Mrs. Reil let me make copies of the teacher textbook,Envision Math, that covered what

the students would be learning in this lesson. The textbook gave a suggested procedure for the

lesson, but I changed up some parts of the procedure like having the students work in groups andusing triangle blocks. I also changed the order of the procedure. The suggested procedure

wanted the teacher to introduce the names of the triangles first and then have the students groupthe triangles correctly, but I reversed the order.

I will be asking a few questions at the close of the lesson (see close for questions). I maybe asked by the students how they are to group the triangles before I present the class with the

correct names of the triangles. If this happens and majority of the students are confused, I will

call the students attention and explain the names and descriptions of each triangle and then have

the students group the triangles by attributes.

Students will be reminded to act appropriately when using blocks.

Differentiation

Struggling learners will be able to ask a neighbor questions while working independently

and also ask the teacher questions while grouping the triangles.

Assessment

Students will be assessed on grouping the triangles correctly according to the trianglesattributes (size and angles) and by answering the questions at the end of the lesson. I will be


3/3

looking to see if the students can correctly name the different kinds of triangles, and be able to

distinguish between the different triangles.

Documents

Triangle Lesson