Lesson Planning of Types of Angles
Students` Learning Outcomes
- They recognize right angle through horizontal and vertical lines.
- They demonstrate acute and obtuse angles via right angle.
Information for Teachers
Types of angles
- Angles are classified according to their size.
- An acute angle is greater than 00and less than 900.
- A right angle equals exactly 900.
- Note: that a right angle is marked on the diagram as a small square.
- An obtuse angle is greater than 900and less than 1800.
- A straight angle equals exactly 1800.
Material / Resources
Writing bard, chalk / marker, duster, toothpicks, glue, clock (paper-made or original)
- 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.
- 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
- Geometry “Simon Says” or call it Geometry Aerobics.
- Develop an agreed-upon 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 upside-down 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.
- 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?