"Angle and the Measurement of Angle" PPT courseware

Description

"Angle and the Measurement of Angle" PPT courseware

Learning objectives of this section:

1. Two definitions of angles and three ways of expressing angles.

2. The measurement unit of angle and the conversion of angle.

The image of corners in life!

What is an angle? There are many examples related to angles in life. Look at the picture below. Can you point out the angle in the picture?

Definition of angle (static)

An angle is a figure consisting of two rays with common endpoints.

Definition of angle (dynamic)

An angle can also be viewed as a figure formed by a ray rotating around an endpoint.

How to express angle

Angle is represented by "∠" and pronounced as "angle". Note: Do not write "<".

There are four ways to express angles:

①Recorded as: ∠ABC or ∠CBA

②Recorded as: ∠B

③Record as ∠α

④Record as ∠1

Get to know flat angle

If the terminal side of an angle continues to rotate until it is in line with the initial side, the angle formed is called a straight angle.

1 straight angle = 180°

Get to know Zhou Jiao

When the end side rotates to coincide with the beginning side, the angle formed is called the circumferential angle.

1 angle = 360°

A judgment question.

(1) The figure formed by two rays is called an angle. ( )

(2) A straight angle is a straight line. ( )

(3) The circumferential angle is a ray. ( )

(4) The figure formed by the rotation of a ray is called an angle. ( )

(5) The length of both sides of an angle has nothing to do with the size of the angle. ( )

Angle conversion:

Example 1 Express 57.32° in degrees, minutes, and seconds.

Solution: First convert 0.32 ° into points,

0.32°＝60′×0.32＝19.2′

Then convert 0.2′ into seconds,

0.2′＝60″× 0.2＝12″

So 57.32°=57 °19′12″

practice

Expressed in degrees, minutes and seconds:

(1) 78.26 °

(2) 48.32°

Solution: (1) 78.26°=78°15′36″

(2) 48.32°=48°19′12″

Thought questions:

After 1 hour, the angle the hour hand of the clock has rotated is ( ), and the angle the minute hand has rotated is ( ). After 15 minutes, the angle the minute hand has rotated is ( ), and the angle the hour hand has rotated is ( ).

Operation:

1 Mathematics textbook page 123: 4

2 "The Midas Coach"

Keywords: teaching courseware for angles and the measurement of angles, download the seventh grade mathematics PPT courseware for the first volume of the Hebei Education Edition, download the seventh grade mathematics slide courseware, download the PPT courseware for angles and the measurement of angles, .PPT format;

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"Angle and the Measurement of Angle" PPT courseware 2:

"Angle and the Measurement of Angle" PPT courseware 2 1. Xiao Ming's house is 5 kilometers away from the school, Xiao Hong's house is 2 kilometers away from the school, Xiao Ming's house, Xiao Hong's house, and the school are on a straight line, then Xiao Hong's house is _ _____km? 2. When farmers dig canals, they first erect posts and pull wires at both ends.

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Update Time: 2024-11-14

This template belongs to Mathematics courseware Hebei Education Edition Seventh Grade Mathematics Volume 1 industry PPT template

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