MA.4.GR.1.1

Informally explore angles as an attribute of two-dimensional figures. Identify and classify angles as acute, right, obtuse, straight or reflex.

Clarifications

Clarification 1: Instruction includes classifying angles using benchmark angles of 90° and 180° in two-dimensional figures.

Clarification 2: When identifying angles, the expectation includes two-dimensional figures and real-world pictures.

General Information
Subject Area: Mathematics (B.E.S.T.)
Grade: 4
Strand: Geometric Reasoning
Date Adopted or Revised: 08/20
Status: State Board Approved

Related Courses

This benchmark is part of these courses.
5012060: Mathematics - Grade Four (Specifically in versions: 2014 - 2015, 2015 - 2022, 2022 and beyond (current))
7712050: Access Mathematics Grade 4 (Specifically in versions: 2014 - 2015, 2015 - 2018, 2018 - 2022, 2022 and beyond (current))
5012055: Grade 3 Accelerated Mathematics (Specifically in versions: 2019 - 2022, 2022 and beyond (current))
5012015: Foundational Skills in Mathematics 3-5 (Specifically in versions: 2019 - 2022, 2022 and beyond (current))

Related Access Points

Alternate version of this benchmark for students with significant cognitive disabilities.
MA.4.GR.1.AP.1: Informally explore angles as an attribute of two-dimensional figures. Limit angles to acute, obtuse and right.

Related Resources

Vetted resources educators can use to teach the concepts and skills in this benchmark.

Formative Assessments

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.

Type: Formative Assessment

Circle the Angles:

Students are asked to circle figures that show angles from a set of figures and then describe the defining attributes of angles.

Type: Formative Assessment

Image/Photograph

Clipart: Geometric Shapes:

In this lesson, you will find clip art and various illustrations of polygons, circles, ellipses, star polygons, and inscribed shapes.

Type: Image/Photograph

Lesson Plans

Angles All Around Us:

This lesson will provide students with the opportunity to see angles all around them. Students will be able to see how and where geometry exist in the real world.  Please note that this lesson focuses on identifying acute, obtuse, right, straight and reflex angles.

Type: Lesson Plan

Geometry at the County Fair:

In this lesson which focuses primarily on angles, students work in collaborative groups to construct a two-dimensional model of a county fair. 

Type: Lesson Plan

Waterpark Angles:

Your students have been hired as a team to build an amazing new slide for the brand new Water World theme park! Their teams will work to build multiple water slides and will decide which angle degree best helps the marble shoot farthest. Throughout the lesson they will be working with identifying and measuring angles while relating angle types and their measurements. Students will also be working with the idea of kinetic and potential energy.

Type: Lesson Plan

Snowflake Geometry: No Two Alike!:

In this lesson students will make snowflakes, promoting creativity and self-expression, and use them to identify geometric terms. It also gives them an opportunity to follow a sequenced set of instructions for a given outcome.

Type: Lesson Plan

Angles All Around Us:

This is a lesson that introduces right, acute, obtuse, reflex, straight angles in a fun and challenging way.

Type: Lesson Plan

Which Angle is Which?:

This is a fun, hands-on activity designed to help students identify and measure obtuse, acute, right, straight and reflex angles. Students create a manipulative tool in their math journals to help them gain understanding of this concept.

Type: Lesson Plan

Points, Lines, and Angles, Oh My!:

In this lesson, students work to identify points, lines, line segments, rays, angles and perpendicular and parallel lines. Students create webs of yarn and analyze the web for geometric properties listed above. A teacher can select which vocabulary terms are appropriate for the class.

Type: Lesson Plan

Angle Your Way Around:

In this lesson students will be introduced to the protractor and benchmark angles, practice reading angles properly, make estimates on angle degrees, measure angles precisely, and participate in a small group activity using their new skills.

Type: Lesson Plan

Runway Rotations:

Students will use small paper airplanes to model rotations required to turn onto a runway. Students will rotate planes 45, 90, 180, 270, and 360 degrees. Students will identify and describe the results of rotations using benchmark angles.

Type: Lesson Plan

Original Student Tutorials

ROC Star: Angle Classification:

Classify and name angles in two-dimensional shapes to help a robot create a path using angles in this interactive tutorial.

Type: Original Student Tutorial

These are the Right Triangles:

Identify right triangles and explain the properties shared by all right triangles in this interactive tutorial.

Type: Original Student Tutorial

Problem-Solving Task

Finding an unknown angle:

The purpose of this task is to give students a problem involving an unknown quantity that has a clear visual representation. Students must understand that the four interior angles of a rectangle are all right angles and that right angles have a measure of 90° and that angle measure is additive.

Type: Problem-Solving Task

Tutorials

Recognizing Acute, Right, and Obtuse Angles:

This Khan Academy tutorial video identifies acute, right, and obtuse angles and justifies each identification. 

Type: Tutorial

Angle Measurements and Circle Arcs:

This Khan Academy tutorial video demonstrates the relationship between the measurement of an angle and the arc of a circle.

Type: Tutorial

Angle Basics:

This Khan Academy tutorial video presents how an angle is formed and labeled.

Type: Tutorial

MFAS Formative Assessments

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.

Circle the Angles:

Students are asked to circle figures that show angles from a set of figures and then describe the defining attributes of angles.

Original Student Tutorials Mathematics - Grades K-5

ROC Star: Angle Classification:

Classify and name angles in two-dimensional shapes to help a robot create a path using angles in this interactive tutorial.

These are the Right Triangles:

Identify right triangles and explain the properties shared by all right triangles in this interactive tutorial.

Student Resources

Vetted resources students can use to learn the concepts and skills in this benchmark.

Original Student Tutorials

ROC Star: Angle Classification:

Classify and name angles in two-dimensional shapes to help a robot create a path using angles in this interactive tutorial.

Type: Original Student Tutorial

These are the Right Triangles:

Identify right triangles and explain the properties shared by all right triangles in this interactive tutorial.

Type: Original Student Tutorial

Problem-Solving Task

Finding an unknown angle:

The purpose of this task is to give students a problem involving an unknown quantity that has a clear visual representation. Students must understand that the four interior angles of a rectangle are all right angles and that right angles have a measure of 90° and that angle measure is additive.

Type: Problem-Solving Task

Tutorials

Recognizing Acute, Right, and Obtuse Angles:

This Khan Academy tutorial video identifies acute, right, and obtuse angles and justifies each identification. 

Type: Tutorial

Angle Measurements and Circle Arcs:

This Khan Academy tutorial video demonstrates the relationship between the measurement of an angle and the arc of a circle.

Type: Tutorial

Angle Basics:

This Khan Academy tutorial video presents how an angle is formed and labeled.

Type: Tutorial

Parent Resources

Vetted resources caregivers can use to help students learn the concepts and skills in this benchmark.

Image/Photograph

Clipart: Geometric Shapes:

In this lesson, you will find clip art and various illustrations of polygons, circles, ellipses, star polygons, and inscribed shapes.

Type: Image/Photograph

Problem-Solving Task

Finding an unknown angle:

The purpose of this task is to give students a problem involving an unknown quantity that has a clear visual representation. Students must understand that the four interior angles of a rectangle are all right angles and that right angles have a measure of 90° and that angle measure is additive.

Type: Problem-Solving Task