Lesson 2 | Shapes and Angles | 4th Grade Mathematics

Objective

Identify and draw right, obtuse, and acute angles.

Common Core Standards

Core Standards

The core standards covered in this lesson

4.G.A.1 — Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.

Geometry

4.G.A.1 — Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.

Foundational Standards

The foundational standards covered in this lesson

3.G.A.1

Geometry

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.

Criteria for Success

The essential concepts students need to demonstrate or understand to achieve the lesson objective

Understand that a right angle is a square corner.
Understand that an acute angle is one that measures less than a right angle.
Understand that an obtuse angle is one that measures greater than a right angle but less than a straight angle.
Understand that a straight angle is one that is formed by three points that are all on the same line.
Determine whether angles are right, obtuse, or acute using a right-angle tool (MP.5).
Draw right, obtuse, and acute angles (MP.5, MP.6).

Tips for Teachers

Suggestions for teachers to help them teach this lesson

Note that students will later see that a right angle is the angle formed by perpendicular lines and measures 90°, more precise definitions of right angles. However, because these terms and concepts have not yet been introduced, the definition is somewhat informal for the time being.
Students are going to create a right-angle tool in this lesson. Have students save this tool for future lessons.

Lesson Materials

Blank Paper (1 sheet per student) — Ideally the paper is circular, though this isn't necessary
Template: Angles (1 per student or small group) — See Anchor Task 1 for how to prepare this material before the lesson.

Fishtank Plus

Unlock features to optimize your prep time, plan engaging lessons, and monitor student progress.

Anchor Tasks

Tasks designed to teach criteria for success of the lesson, and guidance to help draw out student understanding

Problem 1

Sort the angles (cut out from Template: Angles) into as many groups as you like. Be prepared to explain how you sorted your angles.

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

References

EngageNY Mathematics Grade 4 Mathematics > Module 4 > Topic A > Lesson 2 — Concept Development Problem 2

Grade 4 Mathematics > Module 4 > Topic A > Lesson 2 of the New York State Common Core Mathematics Curriculum from EngageNY and Great Minds. © 2015 Great Minds. Licensed by EngageNY of the New York State Education Department under the CC BY-NC-SA 3.0 US license. Accessed Dec. 2, 2016, 5:15 p.m..

Modified by Fishtank Learning, Inc.

Problem 2

Draw an example of a right angle, an acute angle, an obtuse angle, and a straight angle below.

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

References

EngageNY Mathematics Grade 4 Mathematics > Module 4 > Topic A > Lesson 2 — Concept Development Problem 3

Problem Set

Problem Set

Answer Keys

Unlock the answer keys for this lesson's problem set and extra practice problems to save time and support student learning.

Discussion of Problem Set

#1(c) and 1(f) are both right angles. Describe their position. Does the orientation of an angle determine whether it is right, acute, or obtuse?
In #3(a), each ray shared the same endpoint. The shared endpoint is called a vertex. Label the points on your angles in #3. Identify the vertex in #3(b) and 3(c) with your partner.
What is the difference between a straight angle and a line?
Where else in your environment have you seen right angles?
How did the right-angle tool help you recognize and draw angles? How can a right-angle tool help you recognize an acute angle?

Target Task

A task that represents the peak thinking of the lesson - mastery will indicate whether or not objective was achieved

Problem 1

Use the following angles to answer the questions below.

Write the letters of the angles that are:

right angles: _____________________

acute angles: _____________________

obtuse angles: _____________________

straight angles: _____________________

Problem 2

Draw an additional example of each type of angle below.

a. Right angle:

b. Obtuse angle:

c. Acute angle:

d. Straight angle:

Student Response

Create a free account or sign in to view Student Response

Student Response

An example response to the Target Task at the level of detail expected of the students.

Create a free account or sign in to view Student Response

Additional Practice

The Extra Practice Problems can be used as additional practice for homework, during an intervention block, etc. Daily Word Problems and Fluency Activities are aligned to the content of the unit but not necessarily to the lesson objective, therefore feel free to use them anytime during your school day.

Extra Practice Problems

Extra Practice Problems

Answer Keys

Answer keys for Problem Sets and Extra Practice Problems are available with a Fishtank Plus subscription.

Word Problems and Fluency Activities

Help students strengthen their application and fluency skills with daily word problem practice and content-aligned fluency activities.

Lesson 1

Lesson 3

Lesson Map

Topic A: Lines and Angles

Identify and draw points, lines, line segments, rays, and angles.

4.G.A.1 4.MD.C.5

Identify and draw right, obtuse, and acute angles.

4.G.A.1

Identify and draw perpendicular lines.

4.G.A.1

Identify and draw parallel lines.

4.G.A.1

Topic B: Measures of Angles

Use iteration with one physical nonstandard unit to measure benchmark angles.

4.MD.C.5 4.MD.C.6

Understand that an angle that turns through $${{1\over360}}$$ of a circle is called a “one-degree angle” and can be used to measure angles. Use a makeshift protractor to measure benchmark angles.

4.MD.C.5 4.MD.C.6

Measure angles that are less than 180° using a 180° protractor. Distinguish angle measure from other attributes.

4.MD.C.5 4.MD.C.6

Sketch angles of specified measure using a 180° protractor.

4.MD.C.5 4.MD.C.6

Identify and measure angles as turns and recognize them in various contexts.

4.MD.C.5 4.MD.C.6

Topic C: Measures of Adjacent Angles

Decompose angles using pattern blocks.

4.MD.C.7

Solve problems involving the measure of two adjacent angles.

4.MD.C.7

Solve problems involving the measure of more than two adjacent angles.

4.MD.C.7

Measure and sketch angles that are greater than 180°.

4.MD.C.5 4.MD.C.6 4.MD.C.7

Topic D: Shapes and Lines of Symmetry

Analyze and classify triangles based on side length, angle measure, or both.

4.G.A.1 4.G.A.2

Draw triangles from given criteria.

4.G.A.1 4.G.A.2

Analyze and classify quadrilaterals based on parallel and perpendicular lines and the presence or absence of angles of a specified size.

4.G.A.1 4.G.A.2

Draw quadrilaterals from given criteria.

4.G.A.1 4.G.A.2

Identify and draw lines of symmetry in two-dimensional figures.

4.G.A.3

Shapes and Angles

Objective

Common Core Standards

Core Standards

Geometry

Foundational Standards

Geometry

Criteria for Success

Tips for Teachers

Lesson Materials

Anchor Tasks

Problem 1

Guiding Questions

References

Problem 2

Guiding Questions

References

Problem Set

Discussion of Problem Set

Target Task

Problem 1

Problem 2

Student Response

Student Response

Additional Practice

Extra Practice Problems

Word Problems and Fluency Activities

Lesson Map

Request a Demo

Contact Information

School Information

What courses are you interested in?

ELA

Math

Are you interested in onboarding professional learning for your teachers and instructional leaders?

Any other information you would like to provide about your school?

Effective Instruction Made Easy