Lesson Planning of Drawing Angles
Students` Learning Outcomes
- Draw a right angle using a protractor.
- Draw acute and obtuse angles of different measurements using a protractor.
- Draw an angle using a protractor.
- Equal in measure to a given angle
- Twice the measure of a given angle
- Equal in measure of the sum of two given angles
Information for Teachers
- To draw an angle of 50 degrees, first draw a line segment that is to be the one side of the angle.
- Then place the protractor so that its zero line matches with your line segment and that the vertex is in place. Then put a little mark at the spot showing 50 degrees
- Take the protractor off and draw a line through your mark.
Material / Resources
Writing board, chalk / marker, duster, geometry box, textbook
- Recall the construction of vertical line in Horizontal by using Set-Squares.
- Ask any of the students to repeat and then introduce another way of drawing it.
- Say: “We can also use a protractor to construct a right angle”. Using the straight edge of the chalkboard protractor, draw ray AB.
- Say: “We are going to construct a right angle with its vertex of point A. How should we place the center point of the protractor?” (Place the center point of the protractor on point A and the 0 line of the protractor on ray AB” ask a student to demonstrate this at the board with the large protractor.
- Say: “Through which marking on the protractor scale should the other side of the right angle pass?” (90)
- Ask a student to place a point on the board at the 90 mark, label it point C. remove the protractor and draw a ray from point A through point C.
- Ask: “How can we be certain that we have constructed a right angle?
- (It measures 90 we can match against a known right angle, such as the corner of a page in a book).
- What are the correct names for this angle?” (We can call it angle A, Angle BAC, or angle CAB.)
- Ask a student to write the angle names on the board as the others write them in their notebooks. Repeat the procedure by constructing additional angles.
- Assign practice questions from book to work individually and Followed by peer checking.
- Ask them to draw 5 angles of their own choice and label them.