Angles In Mathematics
Subject : Mathematics
Class : JSS 2
Term : Second Term
Week : Week 3
Topic :
Angles
Previous Lesson :
WORD PROBLEMS ON ALGEBRAIC FRACTION
Objective: By the end of this lesson, students will be able to identify, name, and describe the types of angles, and apply this knowledge to solve basic angle problems.
Materials:
- Whiteboard or chalkboard
- Markers or chalk
- Angle measuring tool (optional)
- Worksheets or handouts with angle problems (optional)
Content ;
An angle is a measure of the amount of turn between two lines that meet at a point. We use angles in math to measure things like the corners of shapes and the direction of lines. Angles are measured in degrees, and the symbol for degrees is a small circle (°).
There are three important parts to an angle:
- Vertex – the point where the two lines meet
- Arms – the two lines that form the angle
- Degree measurement – the measure of the amount of turn between the two lines
Now, let’s look at the different types of angles:
- Acute Angle: An acute angle is an angle that measures less than 90 degrees. Here’s an example of an acute angle:
- Right Angle: A right angle is an angle that measures exactly 90 degrees. A right angle looks like the corner of a square or rectangle. Here’s an example of a right angle:
- Obtuse Angle: An obtuse angle is an angle that measures more than 90 degrees but less than 180 degrees. Here’s an example of an obtuse angle:
- Straight Angle: A straight angle is an angle that measures exactly 180 degrees. A straight angle looks like a straight line. Here’s an example of a straight angle:
- Reflex Angle: A reflex angle is an angle that measures more than 180 degrees but less than 360 degrees. Here’s an example of a reflex angle:
Remember, angles are important in math because they help us measure the corners of shapes and the direction of lines. I hope this explanation helped you understand angles better!
Evaluation
- What is an angle? a) A measure of the amount of turn between two lines that meet at a point. b) A type of polygon. c) A type of circle.
- Which part of an angle is the point where two lines meet? a) Vertex b) Arms c) Degree measurement
- Which type of angle measures less than 90 degrees? a) Acute angle b) Right angle c) Obtuse angle
- What is the measure of a right angle? a) 90 degrees b) 180 degrees c) 360 degrees
- Which type of angle measures more than 90 degrees but less than 180 degrees? a) Acute angle b) Right angle c) Obtuse angle
- What is the measure of a straight angle? a) 90 degrees b) 180 degrees c) 360 degrees
- Which type of angle measures more than 180 degrees but less than 360 degrees? a) Straight angle b) Reflex angle c) Acute angle
- What type of angle looks like the corner of a square or rectangle? a) Acute angle b) Right angle c) Obtuse angle
- What type of angle looks like a straight line? a) Acute angle b) Right angle c) Straight angle
- Which type of angle measures exactly 180 degrees? a) Right angle b) Obtuse angle c) Straight angle
Lesson Presentation
Review of previous lesson
Introduction:
Begin by asking the students if they know what an angle is, and have them share their answers with the class. After hearing a few responses, introduce the definition of an angle as “a measure of the amount of turn between two lines that meet at a point.”
Instruction:
- Define and illustrate the parts of an angle (vertex, arms, degree measurement).
- Introduce the types of angles (acute, right, obtuse, straight, reflex) and explain how to identify and measure them.
- Show examples of each type of angle and have students identify and name them.
- Provide practice problems and worksheets for students to work on identifying and measuring angles.
Application:
Have students work in pairs or small groups to create their own angles using straight edges and protractors (if available), and then identify and name each angle they create. Additionally, give students a set of angle problems to solve, either individually or in groups.
Assessment:
Assess student understanding by observing their work during the lesson, and by checking their completed worksheets or handouts. Alternatively, you can administer a short quiz at the end of the lesson to assess their knowledge of angles.
Evaluation
- An angle is a measure of the amount of __________ between two lines that meet at a point.
- The point where two lines meet in an angle is called the __________.
- The two lines that form an angle are called the __________.
- The unit of measurement used to measure angles is __________.
- An angle that measures less than 90 degrees is called an __________ angle.
- An angle that measures exactly 90 degrees is called a __________ angle.
- An angle that measures more than 90 degrees but less than 180 degrees is called an __________ angle.
- An angle that measures exactly 180 degrees is called a __________ angle.
- An angle that measures more than 180 degrees but less than 360 degrees is called a __________ angle.
- The three parts of an angle are the vertex, the arms, and the __________ measurement.
Closure:
Wrap up the lesson by reviewing the different types of angles and their characteristics, and by emphasizing the importance of understanding angles in math. Finally, ask if there are any questions or if there is anything that needs to be reviewed again.
Extension: If time allows, you can extend the lesson by having students explore real-world applications of angles, such as measuring the angles of buildings or the angles of shadows during different times of the day. Alternatively, you can introduce more advanced angle concepts such as complementary and supplementary angles
