First, review the test questions
Topic source 65438+ Harbin, Heilongjiang Province1interview topic on October 6.
On the topic 1, the topic: axisymmetric phenomenon
2. Contents:
3. Basic requirements:
(1) has a blackboard design.
(2) Discover the axisymmetric figure in life and understand the meaning of the axisymmetric figure.
(3) Pay attention to clarity and focus in teaching.
(4) Please complete the trial content within 10 minutes.
Question 1. Why should we study the phenomenon of axial symmetry?
2. What are the three common Pythagorean numbers?
Second, the analysis of test questions
teaching process
(A) the introduction of new courses
Show the emblem of the International Congress of Mathematicians and ask: Does the emblem have any special meaning? What are the mathematical mysteries?
(2) Explore new knowledge
Activity 1: Show the "pythagorean friend's floor tile map".
Guide students to discover and understand some quantitative relations of isosceles right-angled triangles in graphics, and ask questions: What are the relations between the three sides of isosceles right-angled triangles? Guide the students to arrange by area method, and draw the conclusion that the sum of squares of two right angles of isosceles right triangle is equal to the square of hypotenuse.
Question 1: Does the general right triangle have a similar law? Guide students to explore the law by using the area in the grid diagram, and draw the conclusion that the sum of squares of two right-angled sides of a right-angled triangle is equal to the square of the hypotenuse.
Second, the examination questions review topic source 65438+ Harbin City, Heilongjiang Province1October 6 afternoon interview topic
Talk about the topic 1. Topic: Axisymmetric phenomenon.
2. Contents:
3. Basic requirements:
(1) has a blackboard design.
(2) Discover the axisymmetric figure in life and understand the meaning of the axisymmetric figure.
(3) Pay attention to clarity and focus in teaching.
(4) Please complete the trial content within 10 minutes.
Title of defense 1. Why should we study the phenomenon of axial symmetry?
2. How did you design and explore the axisymmetric phenomenon in the teaching process of this class?
Second, the analysis of test questions
teaching process
(A) the introduction of new courses
Teacher's Description: Students, the teacher will tell you a short story before class. (Play animation) There is a beautiful butterfly collecting nectar among the flowers by the river. Suddenly! A dragonfly flew in front of it, and the butterfly said angrily, "Who annoyed me?" Dragonfly said with a smile, "why don't you even know your family?" I am here to play with you. " At this time, the butterfly became more angry and said, "You are a dragonfly and I am a butterfly. How can we be a family? " Then, the dragonfly landed on a nearby leaf and said, "You don't know this. Not only dragonflies and butterflies are family, but also some leaves and many objects around us are family with us. " The story is over, class. Do you understand what dragonfly said?
Presupposition: The students talked a lot, but they didn't understand the meaning of skimming the water. Students encounter bottlenecks here, and I will take advantage of the situation to introduce the topic. This class will learn the phenomenon of axial symmetry.
(B) to generate new knowledge
Activity 1: Ask students to give some examples of axisymmetrical figures in their lives to test their understanding of the essential characteristics of axisymmetrical figures. Then present some axisymmetric figures on the big screen to guide students to observe, and then summarize the similarities and differences of these figures by analogy with what they have learned before.
Q: These beautiful figures come from life. What are the similarities between these figures? Describe it in your own words.
Default: The left and right parts of the graph are symmetrical.
Follow-up: Can you fold the window grilles in the picture in half along a straight line so that the parts on both sides of the straight line completely overlap? What about other graphics?
Default: You can find a line to make the left and right completely coincide.
Activity 2: Group discussion. Through observation, guide students to carry out inductive verification, and operate the "origami" experiment to summarize the related concepts of axisymmetric figure and axis of symmetry.
Default: If a graph is folded in half along a straight line, the graphs on both sides can completely overlap, and this graph is an axisymmetric graph. The straight line where the crease lies is called the symmetry axis.
Guide the students to observe their folded figures and draw the symmetry axis to see if they can find anything. On the basis of deskmate communication, guide students to sum up in time and get the concept of symmetry: if a graph is folded along a straight line and can completely coincide with another graph, we call these two graphs symmetrical about this straight line, and this straight line is called the symmetry axis.
The above are the junior high school math questions I compiled, hoping to help you.