What does the apex decide and what does the edge decide?

The so-called angle is composed of two rays drawn from a certain point. The vertices determine the position of the feet, and the edges determine the size of the corners.

Second-grade elementary school students have a big problem in learning this new part of the knowledge.

In class, the teacher points to acute angles, but the classmates are right angles or obtuse angles! In short, there is still some ambiguity and lack of clarity about the three different corners.

So, how to use the right method to master the 4 knowledge points of this unit?

The first knowledge point: right angle, acute angle, obtuse angle.

The basis for the judgment is that the two sides of the right angle are perpendicular, and the right angle symbol is generally marked. Acute angles are comparatively smaller and smaller than right angles. The obtuse angle is comparatively larger and larger than the right angle.

Looking at the first major question in the picture above, correctly distinguishing these three angles is the primary requirement of this unit. In addition, this part of the content is learned in the upper grades of elementary school, junior high school, and high school, so it is necessary to lay a solid foundation.

The second knowledge point: can correctly count the number of three kinds of angles.

Looking at the third question in the picture above, there are a lot of mistakes.

The correct method of observation must be possessed. In the 3 diagrams of the 3rd question, you need to find out the angle first, and you must observe the place where the line segments are connected in the diagram, if the line segments are connected, it is the angle, because the characteristic of the angle is that it contains a vertex and two edges. The place where this question is easy to make mistakes is that the line segments are not connected, although they look like angles, they are not angles, and they need to be paid attention to.

The correct answer is: the first figure 1 acute angle, 1 right angle, 2 acute angles; The second figure contains 0 acute angles, 2 right angles, 3 obtuse angles; The third figure contains 1 acute angle, 0 right angles, and 5 obtuse angles.

The third knowledge point: how to draw pictures.

Look at the third question in the picture above, second-year students, you must be able to draw corners, this is the basic requirement.

The method of drawing corners has been emphasized many times, but some children have developed a bad habit of drawing without a ruler, and it is easy to draw ugly figures. Moreover, the three corners are not the same, and the size should be paid attention to.

The fourth knowledge point: count the number and types of corners in the closed graph.

Looking at the picture above, this kind of question is not difficult, why do students make so many mistakes?

The observation is insufficient, and the difference between the three angles is plausible and not clear enough. When answering the questions, we must learn to observe and determine the names of the horns according to the different characteristics of the three angles.

To sum up: the content of this unit, as long as you correctly grasp the above 4 knowledge points, it is enough. Also, you need to practice a little more, and when dealing with various problems, you must use your brain to think. As long as you study hard, you can basically master it.

Hope it works for you!

In the understanding of angles, the vertices determine the degree, and the edge points determine the length.

Wrong.

Explanation Analysis: In geometry, an angle is a geometric object composed of two rays with a common endpoint. These two rays are called the edges of the corner, and their common endpoints are called the vertices of the corner.

Ordinary angles are assumed to be on the Euclidean plane, but angles can also be defined in Euclidean geometry. In the original sentence, "the angle is composed of a vertex and two line segments" refers to a line segment and not a ray, so it is wrong.

Euclid, the father of geometry, defined an angle as the relative slope of two non-parallel straight lines in a plane. Procruz thought that an angle might be a trait, a quantifiable quantity, or a relation.

Eudemo considered an angle to be a deviation from a relative straight line, and Caboos of Antioch considered an angle to be the space between two intersecting straight lines. Euclid considered angles to be a relation, but his definitions of right, acute, and obtuse angles were quantified.

An angle is formed by two rays emitting from the same point in different directions. This point where the two rays start together is called the vertex of the angle. The two rays of this angle are called the two sides of the angle.

In geometry, two lines meet to form an angular point, and the corners of the polygon and polyhedron are the vertices.

In fields such as mathematics and computer science, capstone has different meanings in different disciplines:

1) In plane geometry, a vertex is where two sides of a polygon intersect, or the common endpoint of two sides of a finger angle.

3) In graph theory, a vertex can be understood as an orange manuscript stool, while a graph is composed of a set of vertices and the connections between vertices.

4) In computer graphics, a vertex is a point in an empty circle and is generally represented by its coordinates. Two points can determine a straight line, and three points can determine a plane.

5) In particle physics, a vertex is the point at which particles interact, for example, the point where two particles react to the collision in LHC is the vertex.

Question 1: What kind of circle is called an angle? What are vertices and what are edges. What kind of circle is called a horn?

The shape of a semicircle.

The two oblique places of the two vertical edges are called corners.

What is the apex of the pants field?

The top point of the top of the top of the pure denier.

What is the side of the apex?

The most edge of objects and places.

Question 2: What are the vertices of the angle Two rays are drawn from a point, and this point is called the vertex of the angle, and these two rays are called the edges of the corner.

In the number bridge manuscript, .Static definition of an angle: The graph composed of two rays with a common point is called an angle, this common endpoint is called the vertex of the angle, and these two rays are called the two edges of the angle. Birds.

Dynamic definition of angle: the shape formed by a ray rotating from one position to another around its endpoint is called an angle, the endpoint of the rotated ray is called the vertex of the angle, the ray at the beginning position is called the beginning edge of the angle, and the ray at the end position is called the end edge of the angle.

This sentence is incorrect.

An angle is composed of a vertex and two rays terminated by a lead vertex, and the vertex can only determine the position of the angle, but not the size of the angle, which depends on the degree of deviation of the two rays.

No, the car cover is right. An angle is a graph consisting of two lines leading from a fixed point on a plane, and the point is the vertex of the angle. Where the vertex is Qiaoqiao, the horn is where the first trouble is, so the position of the horn is determined by the vertex, but the size is not.

Two rays are drawn from a point, and the resulting figure is called an angle, and these two rays are called the edges of the angle, and the angle is usually represented by a symbol;

So it is true to say that the vertices of the horns determine the position of the horns

So the answer is:

A corner has only one vertex and one edge. Wrong.

Correct: an angle is made up of a vertex and two edges.

In geometry, an angle is a geometric object made up of two rays with a common endpoint. These two rays are called the edges of the corner, and their common endpoints are called the vertices of the corner.

In planar geometry, an angle has only one vertex and two edges.

Hope it helps.

According to the meaning of the angle: the figure formed by the collision of two chain rays drawn from a point is called an angle; Ridiculously respectful: all corners are made up of a vertex and two edges; So the answer is: