Lesson Planning of Types of Angles
Subject Mathematics
Grade 5^{th}
Students` Learning Outcomes
 They recognize right angle through horizontal and vertical lines.
 They demonstrate acute and obtuse angles via right angle.
Information for Teachers
Zero Angle
Obtuse Angle
Right Angle
Acute Angle
Types of angles
 Angles are classified according to their size.
 An acute angle is greater than 0^{0}and less than 90^{0}.
 A right angle equals exactly 90^{0}.
 Note: that a right angle is marked on the diagram as a small square.
 An obtuse angle is greater than 90^{0}and less than 180^{0}.
 A straight angle equals exactly 180^{0}.
Material / Resources
Writing bard, chalk / marker, duster, toothpicks, glue, clock (papermade or original)
Introduction
 Act and demonstrate by sitting in three directions:

 Straight up bend down
 Stretch back and introduce right, acute and obtuse angles.
 Draw figure on board: L is right, V is acute.
 Acute is “A cute angle”.
Clock faces work well for playing with angles. 3 o`clock make right angles from the minute hand and 2 o`clock is an acute angle. 4 o`clock makes an obtuse angle.
Development
Activity 1
 With a movement of your arm along the elbow reinforce acute and obtuse along a straight line.
 Repeat to explain the difference between right angle and other angles.
 The students use their arms and legs to make angles by bending and moving (physical exercise add pictures or sketch if possible)
 Make the angles with toothpicks, glue them on to paper, and label them.
 Find five objects in your home that have right angles in them.
 Draw some angles on the board and ask them to mark the angles as acute, right, obtuse, or straight (whole class activity)
 Recall the concept of horizontal and vertical lines and introduce the angle between them as right angle by asking does it make an L shape?
 Assign pair work of labeling angles (questions can be assigned from a book or prepare a worksheet)
 Invite one or two students to recap the points of today.
 Collect students work to check later.
Sum up / Conclusion
 Conclude the lesson
Assessment
 Geometry “Simon Says” or call it Geometry Aerobics.
 Develop an agreedupon set of physical gestures to represent the vocabulary terms you have studied.
 Line: both arms outstretched, fingers pointing in opposition directions.
 Segment: same as above, but with hands balled into fists (endpoints)
 Point: one hand makes a fist.
 Perpendicular: left arm straight across the chest; right arm straight across.
 The chest; right arm bent at the elbow resting on the left arm, forming an upsidedown T.
 Parallel: forearms held parallel, like the touch down symbol.
 Acute angle: arms make an acute angle
 Obtuse angle: arms make an obtuse angle etc.
Follow up
 Students all stand up; the teacher or leader calls a vocabulary term, simultaneously making one of the gestures, but not necessarily the one that goes with the term. Students must respond with the correct gestures, or else they`re out and have to sit down. Continuous until you have only one person still standing; that person becomes the leader in the next round. This is particularly fun if the teacher is not the leader, and makes the wrong gestures, because a good many of the students usually try to copy the teacher`s gesture.
 Can someone show me a right angle?
 Can someone show me an acute angle?
 Can someone show me an obtuse angle?