Lesson Overview
In this lesson, students discover what angles are and how they are formed. Students will learn different types of angles, such as acute, obtuse, right, and straight angles. They will also learn how angles are measured in degrees. Using Ziggy the Turtle Robot, students will practice drawing angles by programming Ziggy to turn and move in different directions.
What You Will Learn
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Understand angles in geometry
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Recognise the angle symbol
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Identify different types of angles
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Understand interior and exterior angles
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Use the Turn block to draw angles
Exploring Angles in Geometry
An angle is formed when two straight lines or rays meet at one common point.
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The two rays are called the sides of the angle.
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The meeting point is called the vertex.
Angles Around Us
Angles appear everywhere in our daily life, such as:
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Clothes hangers
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Scissors
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Partially opened doors
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Table edges and rulers
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Pyramid shapes
Symbol of an Angle
The symbol used to represent an angle is: ∠ Angles are measured using degrees (°):
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Full rotation = 360°
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Half turn = 180°
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Right angle = 90°
Two or more angles on a straight line always add up to 180°.
Types of Angles
1.
Acute Angle
Measures less than 90°.
Measures less than 90°.
2.
Obtuse Angle
Measures between 90° and 180°.
Measures between 90° and 180°.
3.
Right Angle
Measures exactly 90°.
Measures exactly 90°.
4.
Straight Angle
Measures exactly 180°.
Measures exactly 180°.
Rotation Direction
The Turn block changes Ziggy’s direction:
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Turn left or right
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Use a number to set the angle
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A full turn equals 360°
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To turn Ziggy backward, turn left or right by 180°
Interior and Exterior Angles
Interior Angle
The angle that is formed inside a shape.
Exterior Angle
Exterior Angle The angle that is formed outside a shape.
Note: To draw angles correctly, Ziggy draws the exterior angle first.
Activity 1: Drawing a Right Angle
Steps:
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Draw a vertical line.
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Turn right 90 degrees.
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Draw a horizontal line.
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Upload the Code to the Micro:Bit Board
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Put Ziggy on a paper, and turn Ziggy On
Activity 2: Drawing an Acute Angle
To make an acute angle of 30°, we should know that 30 is the interior angle, and we have to calculate the exterior angle as follows:
Exterior angle = 180° − 30° = 150°
Steps:
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Choose an event ( when button A is pressed )
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Move Pen Down
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Draw a straight line of 100 mm
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Turn right 150° ( interior 30° ).
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Move forward 100 mm.
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Move Pen Up
Test the code by uploading it, turning the Ziggy on, and pressing button A.
Activity 3: Drawing an Obtuse Angle
To make an obtuse angle of 140°, we should know that 140 is the interior angle, and we have to calculate the exterior angle as follows:
Exterior angle = 180° − 140° = 40°
Steps:
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Choose an event ( when button A is pressed )
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Move Pen Down
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Draw a straight line of 100 mm
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Turn right 40° ( interior 140° ).
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Move forward 100 mm.
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Move Pen Up
Test the code by uploading it, turning the Ziggy on, and pressing button A.
Challenge
Draw the letter F using Ziggy.
