Primary Type: Formative Assessment
Status: Published
This is a resource from CPALMS (www.cpalms.org) where all educators go for bright ideas!
Resource ID#: 68856
All About Angles
Students are asked to identify right, acute, and obtuse angles in a two-dimensional figure, and explain the differences among these types of angles.
Subject(s): Mathematics
Grade Level(s): 4
Intended Audience: Educators
Freely Available: Yes
Keywords: MFAS, angles, acute, right, obtuse, degrees
Resource Collection: MFAS Formative Assessments
ATTACHMENTS
MFAS_AllAboutAngles_Worksheet.docx
FORMATIVE ASSESSMENT TASK
Instructions for Implementing the Task
This task may be implemented individually, in small groups, or in a whole-group setting. If the task is given in a whole-group setting, the teacher should ask each student to
explain his or her thinking and strategy.
1. The teacher provides the student with the All About Angles worksheet and a protractor.
2. The teacher points to the shape on the top of the worksheet, and reads to the student, “Look at this figure. Put the letter O on an obtuse angle, put the letter R on a
right angle, and put the letter A on an acute angle.”
3. If the student labels the acute, right, and obtuse angles on the outside of the figure, the teacher should ask the student to point to where each type of angle is formed
in the two-dimensional figure.
4. Then the teacher says, “Explain the differences between acute, obtuse, and right angles.”
5. If the student struggles to explain, the teacher may prompt the student by asking, “How would you define each angle? What do you know about possible degree
measures for each type of angle?”
Note: If the student describes obtuse angles as greater than 90 degrees, it is important for the teacher to discuss this further so the student understands that obtuse
angles are greater than 90 degrees and less than 180 degrees.
TASK RUBRIC
page 1 of 3 Getting Started
Misconception/Error
The student cannot identify right, acute, and obtuse angles in the quadrilateral.
Examples of Student Work at this Level
The student is not able to label correctly the right, acute, and obtuse angles on the quadrilateral. The student also makes errors explaining the different types of angles.
Questions Eliciting Thinking
What do you know about the degree measure of an acute angle? What about obtuse angles? Right angles?
Can you explain how you decided where to put each label on the diagram?
Can you draw an acute, right, and obtuse angle? How did you decide how to draw each angle?
Can you explain how to use a protractor to measure an angle?
Instructional Implications
Clearly define acute, right, and obtuse angles. Explain to the student that each type of angle can be classified based on the measure of the angle, which can be determined
using a protractor.
Provide examples of angles with various measurements and orientations. If needed, review how to use a protractor to measure an angle. Then have the student practice
measuring angles and classifying them as acute, right, or obtuse.
Model for the student how to identify types of angles within shapes, such as pattern blocks. Then pair the student with a classmate to practice finding and classifying angles
within shapes.
Consider using MFAS tasks Lines, Rays, and Line Segments and Locating Points, Lines, and Rays (4.G.1.1) to assess the student’s understanding of points, lines, line
segments, and rays.
Making Progress
Misconception/Error
The student cannot clearly explain the difference between acute, obtuse, and right angles.
Examples of Student Work at this Level
The student correctly identifies right, acute, and obtuse angles in the quadrilateral, but provides a general or vague explanation of right, acute, and obtuse angles. The
student:
Believes that acute and obtuse angles are a fixed degree measure rather than a range of measures.
Says that acute angles are skinny and obtuse angles are wide.
Makes errors in describing the degree measures of each type of angle.
Questions Eliciting Thinking
Can you describe each type of angle in terms of its measure?
Can you identify three different degree measures of acute angles? What about obtuse angles?
You are correct that obtuse angles measure greater than 90 degrees. Are all angles greater than 90 degrees obtuse?
Instructional Implications
Explain that, unlike the right angle which measures exactly 90 degrees, acute and obtuse angles can have a range of measures. Clearly define acute angle, obtuse angle,
and right angle for the student in terms of angle measure. Provide numerous examples of angles in a variety of orientations and have the student measure and classify each
angle based on its measure.
Encourage the student to go on an angle hunt with a partner by searching for angles in magazines. Have the student use tracing paper to trace the angle. Then have the
page 2 of 3 student measure each angle with a protractor and classify the angle as acute, obtuse, or right. Have the student justify the classification to his or her partner.
Got It
Misconception/Error
The student provides complete and correct responses to all components of the task.
Examples of Student Work at this Level
The student correctly identifies right, acute, and obtuse angles in the quadrilateral. He or she clearly explains that:
An obtuse angle measures greater than 90 degrees but less than 180 degrees.
An acute angle measures between zero and 90 degrees.
A right angle measures exactly 90 degrees.
Questions Eliciting Thinking
If I bisect a 90 degree angle, what is the measure of each of the new angles formed?
What shape can have four sides of equal length, two obtuse angles, and two acute angles?
Instructional Implications
Consider using MFAS task Parallel and Perpendicular Sides (4.G.1.1) to assess the student’s understanding of parallel and perpendicular lines within two­dimensional figures.
Consider using MFAS tasks Sketching Quadrilaterals and/or Sketching Triangles (4.G.1.2) to assess the student’s understanding of classifying figures based on the presence
or absence of parallel and perpendicular lines and angle measure.
ACCOMMODATIONS & RECOMMENDATIONS
Special Materials Needed:
All About Angles worksheet
Protractor
SOURCE AND ACCESS INFORMATION
Contributed by: MFAS FCRSTEM
Name of Author/Source: MFAS FCRSTEM
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.4.G.1.1:
Description
Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify
these in two-dimensional figures.
page 3 of 3