Primary Type: Formative Assessment
Status: Published
This is a resource from CPALMS (www.cpalms.org) where all educators go for bright ideas!
Resource ID#: 36599
Composing a Trapezoid
Students use triangles to compose a trapezoid.
Subject(s): Mathematics
Grade Level(s): 1
Intended Audience: Educators
Freely Available: Yes
Keywords: MFAS, MAFS.1.G.1.2, Triangle, trapezoid, compose, build, composite shape
Resource Collection: MFAS Formative Assessments
FORMATIVE ASSESSMENT TASK
Instructions for Implementing the Task
1. The teacher provides the student with 5 – 10 green triangles from the pattern block set.
2. The teacher asks the student, “If you were to build or compose a trapezoid using these triangles, how many triangles do you think you would need?”
3. After providing the student with sufficient time to think and reply, the teacher says, "Can you now compose the trapezoid from the triangles?"
4. After the student composes the trapezoid, the teacher shows the student the red trapezoid, noting that it is the exact same size and shape (congruent) as the trapezoid
made from the three green triangles.
5. Then, the teacher provides 3 – 5 red trapezoids for the student and asks, “Can you use these trapezoids to build, or compose, a different shape?”
6. The teacher provides the student sufficient time to work with the trapezoids to compose a larger shape and then asks, "Can you tell me about the shape you composed
from the trapezoids?"
TASK RUBRIC
Getting Started
Misconception/Error
The student is unable to compose the trapezoid without significant prompting from the teacher.
Examples of Student Work at this Level
The student attempts to compose the trapezoid from the triangles, but is not successful. However, with prompting from the teacher, the student eventually composes the
trapezoid, but cannot go any further with the task.
The student may be able to compose the trapezoid with prompting but does not know why it is a trapezoid.
The student’s attempt at composing the trapezoid is nonsystematic and based on trial­and­error.
Questions Eliciting Thinking
What do you know about a trapezoid? What does it look like? How many sides does it have?
What do you know about this triangle? Can you put two of them together to compose a rhombus?
page 1 of 3 What about a trapezoid? Can you compose a trapezoid?
Instructional Implications
Provide the student with opportunities to compose rhombi and trapezoids using triangles. After the student is able to do so, provide opportunities to use the rhombi and
trapezoids to compose hexagons.
Provide the student with opportunities to complete pattern block fill ins. Initially, these should have the outline of each shape traced, and the student should place shapes
where they fit. Next, have the student fill in more abstract shapes with pattern blocks in which many different combinations are possible.
Work on the relative position of objects with the student, using terms such as behind, in front of, or next to.
Allow the student to work on the composition of shapes. Consider using the kindergarten MFAS task, “Compose A Rectangle.”
Moving Forward
Misconception/Error
The student is unable to compose any further shapes after the trapezoid is composed.
Examples of Student Work at this Level
The student is able to compose the trapezoid from the triangles independently, but he or she cannot compose another shape from the trapezoids even with prompting
from the teacher.
Questions Eliciting Thinking
What makes a shape a trapezoid? Which of the pattern blocks is an example of a trapezoid?
What if you put these two trapezoids together with a pair of full sides touching. Can you make a new shape? Tell me about a shape you could make?
What if you turn one of the trapezoids over? Can you get put the two together with a pair of full sides touching now?
Instructional Implications
Provide the student with opportunities to compose rhombi and trapezoids using triangles. After student is able to do so, provide opportunities to use the rhombi and
trapezoids to compose hexagons.
Provide the student with opportunities to complete pattern block fill ins. Initially, these should have the outline of each shape traced, and the student should place shapes
where they fit. Next, have the student fill in more abstract shapes with pattern blocks in which many different combinations are possible.
Allow the student to create his or her own outline puzzles (or pattern block fill ins), and work on solving other student’s puzzles.
Almost There
Misconception/Error
The student is unable to compose another shape from the trapezoids without prompting from the teacher.
Examples of Student Work at this Level
The student can correctly compose the trapezoid from the triangles, but he or she may be unable to compose or describe the new shape(s) that was composed from the
trapezoids.
The student also may not be intentional in his or her composition of the new shapes.
Questions Eliciting Thinking
What do you know about this new shape? Does it look like any other shapes you know?
Can you arrange these trapezoids in a different way? What kind of shape is that?
Instructional Implications
Provide opportunities for the student to compose new shapes from composite shapes and to describe those new shapes using appropriate vocabulary.
Allow the student opportunities to solve puzzles using simple origami shapes. For example, students might fold a square of paper once to make a triangle or non-square
rectangle.
Got It
Misconception/Error
The student has no misconceptions or errors.
Examples of Student Work at this Level
The student is able to compose the trapezoid from the triangles and then a new shape from the trapezoids. The student is also able to name and describe new shape(s)
composed from the trapezoids.
page 2 of 3 Note: The level IV student is able to compose shapes intentionally and knows how to arrange each shape without much time or effort.
Questions Eliciting Thinking
Are there other ways to use these triangles to compose a different trapezoid? Do all trapezoids look like this one?
Instructional Implications
Have the student work on composing other trapezoids using triangles, squares, and rhombi from the pattern block set.
Have the student create his or her own fill in the space puzzles with pattern blocks. This requires the student to leave empty space somewhere in the design so that a
pattern block (or blocks) could complete it.
Allow the student opportunities to solve puzzles using simple origami shapes. For example, students might fold a square of paper once to make a triangle or non-square
rectangle.
Work on the student’s spatial structuring. One way to develop this type of thinking is to show how a rectangle can be tiled with squares lined up in rows and columns.
Initially, the student may draw or place shapes inside the rectangle, but does not cover the entire region. Eventually, the student will align the squares vertically and
horizontally to compose the rectangle as a collection of rows and columns of squares.
ACCOMMODATIONS & RECOMMENDATIONS
Special Materials Needed:
Triangles and trapezoids from the Pattern Block set
SOURCE AND ACCESS INFORMATION
Contributed by: MFAS FCRSTEM
Name of Author/Source: MFAS FCR-STEM
District/Organization of Contributor(s): Okaloosa
Is this Resource freely Available? Yes
Access Privileges: Public
License: CPALMS License - no distribution - non commercial
Related Standards
Name
MAFS.1.G.1.2:
Description
Compose two-dimensional shapes (rectangles, squares, trapezoids, triangles, half-circles, and quarter-circles) or threedimensional shapes (cubes, right rectangular prisms, right circular cones, and right circular cylinders) to create a
composite shape, and compose new shapes from the composite shape.
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