"Measurement of Angles" PPT

Description

"Measurement of Angles" PPT

Part One: Lesson Objectives

1. Understand the necessity of introducing a protractor in the learning process, understand the unit of measurement of angles, and establish an representation; be able to establish the unit of measurement of angles by measuring angles, and establish the representation of an angle of 1 degree; be able to establish the size of an angle by measuring angles Quantitative concept, the size of the feeling angle has nothing to do with the length of the side drawn.

2. Through the process of own observation and communication, understand the structure and function of the protractor, and through exploration and practice, summarize the method of using the protractor to measure angles. Initially learn to use a protractor to measure angles.

3. Actively participate in angle measurement learning activities, gain successful experience in the process of exploring angle measurement methods, and develop an interest in discovering mathematical laws in practice.

Measurement of angles PPT, part 2: exploring new knowledge

Which of the two corners below is larger? How much bigger?

Use the corners on a triangle ruler to measure and compare.

Still don't know exactly how much greater ∠2 is than ∠1.

To accurately measure the size of an angle, it should be measured in an appropriate angle unit.

People divide the circle into 360 equal parts, and use the angle subtended by 1 part as the unit of angle measurement. Its size is 1 degree, recorded as 1°.

The angle subtended by each part measures 1°.

Based on this principle, people made a tool for measuring angles: a protractor.

A protractor is made by dividing a semicircle into 180 equal parts.

How to measure angles with a protractor?

First: The center of the protractor coincides with the vertex of the angle.

Second: The 0° scale line coincides with one side of the angle.

Third: The scale on the protractor corresponding to the other side of the angle is the degree of the angle.

Measurement of angles PPT, Part 3: Consolidation exercises

Fill it out

1. Two rays are drawn from a point, and the resulting ( ) is called ( ). These two ( ) are called the sides of the angle, and the angle is usually represented by the symbol ( ).

2. The measurement unit of angle is ( ), represented by the symbol ( ). The size of the angle is measured with ( ).

3. The size of the angle has nothing to do with the ( ) on both sides of the angle. The wider the two sides of an angle diverge, the angle ( ). The size of the angle has nothing to do with ( ).

5. When measuring an angle, the center of the protractor coincides with ( ), the 0° scale line coincides with ( ), and the scale on the protractor opposite to the other side of the angle is the angle ( ).

Measurement of angles PPT, Part 4 content: Class summary

What did you gain from today’s study?

Today I learned to use a protractor to measure the size of an angle, that is, the center point of the protractor coincides with the vertex of the angle, the 0° scale line of the protractor coincides with one side of the angle, and then look at the number of scales on the other side of the angle.

Keywords: Free download of PPT courseware for mathematics in the first volume of the fourth grade of the People's Education Press, download of PPT on the measurement of angles, .PPT format;

For more information about the "Measurement of Angles" PPT courseware, please click on the "Measurement of Angles" PPT tab.

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Update Time: 2024-09-08

This template belongs to Mathematics courseware People's Education Press Fourth Grade Mathematics Volume 1 industry PPT template

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