Describe different types of Angles

Lesson Plan of Describe different types of Angles

Students` Learning Outcomes

  • Describe adjacent, complementary and supplementary angles.

Information for Teachers

  • Students already know about angles.
  • Adjacent Angles: two angles with common vertex, one common arm and uncommon interior are called Adjacent Angles.

 

  • Angles x and y are adjacent because they share a ray [line in red] and a vertex [point in black called D]
  • Complementary Angles:  two angles whose sum of measures is 900 are called Complementary angles.
  • Complementary may or may not be adjacent.
  • If the angles are not adjacent, still they can be called complementary angles, as given below are complementary angles because the sum of their measures is 900.

 

 

  • For example the following pairs of non-adjacent angles are also complementary as their sum is equal 900 degrees.

 

 

  • Supplementary Angles: two adjacent or non-adjacent angles are Supplementary if their sum is equal to 1800 degrees.

 

 

  • Examples:
  • 400and 1400 are supplementary angles of each other.
  • 930and 870 are supplementary angles of each other.
  • The following pairs of non-adjacent angles are also supplementary angles as their sum is equal to 1800.

 

 

  • Consult textbook at all the steps wherever required.

 

Material / Resources

Writing board, chalk / marker, duster, textbook

Introduction

  • Ask the students to look for following words in English dictionary [this can be given as home work one day before]
  • Adjacent, complementary and supplementary
  • Inquire the meanings and then introduce one by one.

 

Development

Activity 1

  • Activities for Adjacent Angles;
  • Supplementary Angles:
  • Ask students to draw a straight line in the notebooks. Take any point on the line and draw another line to form any angle. [Show figure] 
  • Ask them to measure the angles on both sides and add the degrees of both.
  • Raise your hands if you get 1800 as the sum [they all will raise as they finish measurements]
  • Tell them that these angles are called supplementary angles.
  • Also introduce that supplementary angles are not necessary adjacent. Ask children to make / find some supplementary angles.

Activity 2

  • Complementary Angles:
  • Ask the students to first draw a right angle and then draw a line starting from its vertex cutting through the right angle making another angle.

 

  • Ask them to measure both the angles and add the degrees and then introduce the term complementary angles.
  • Divide the students in groups and ask them to think about the definitions discussed.
  • Ask “can we consider following as examples of Supplementary angles, if yes then why?” There are Adjacent angles of a four-cornered room.
  • Adjacent angles of a window; Time of 6:00 with the second hand pointed at 3,
  • Two adjacent ends of a piece of papers.
  • Ask “can we considered following as examples of Complementary angles, if yes then why.
  • Adjacent angles of a four-cornered room
  • Adjacent angles of a window
  • Time of 6:00 with the second hand pointed at 3
  • Two adjacent ends of a piece of paper
  • Ask ‘can we consider following as examples of Complementary angles, if yes then why?
  • Examples of Complementary angles:
  • Time of 3:00 with the second hand pointed at 2.
  • Wind up the lesson by inviting students one by one in front of class to repeat verbally.

 

Sum up / Conclusion

  • Review new learning with the students.
  • Ask them to define the following:
  • Adjacent Angles: two angles with common vertex, one common arm and uncommon interior are called Adjacent Angles.
  • Complementary Angles: two angles whose sum of measures is 900are called Complementary Angles.
  • Supplementary Angles: two angles are supplementary if they add up to 1800 degrees.

 

Assessment

  • Feedback of students on related examples of activities will help to assess them.
  • Draw different angles on the board as given in examples and ask them to identify pairs with respect to complementary, supplementary and adjacent.

 

 

Follow up

  • Encourage students to look for angles in the corners of roofs and walls and other places and report back to class.

 

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