AnglesMs. Henson’s 4th Grade Class

Learning Objectives• The student will analyze and

measure angles using a protractor.

• The student will identify angles as right angle, acute angles, and obtuse angles.

• The student will build and draw right, acute, and obtuse angles.

What is an angle?Two rays with a

common endpoint form

an angle.

• The meeting point of two lines or two rays is called the vertex.

Vertex

Angles are measured in units called degrees. A protractor is the tool we use to measure angles in degrees.

120° Degree

Sign

Angles FoldableMaterials Needed: Colored PaperMarkersScissors

Types of Angles

An angle that measures less

than 90°

An angle that measures

exactly 180°

Acute Angles

An angle that measures

exactly 90°

An angle that measures more

than 90°

Straight Angles

Right Angles

Obtuse Angles

Naming and Measuring Angles

https://www.brainpop.com/math/geometryandmeasurement/angles

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Your turn• Measure each angle on your

worksheet using your protractor. • Label each angle with the

measurement (in degrees) • Identify each angle as an acute,

right, obtuse, or straight angle.

Reach for the Stars• Draw 3 triangles.• How many angles are in each

triangle?• Measure the angles of each

triangle and add together to get a total in degrees.• What do you notice about the total

for each triangle?

Ticket Out the Door• Use your

protractor to draw the 4 different types of angles we learned today.

• Label each angle with their name and degree measurement.