"Rule and Compass Drawing" PPT Courseware 2

Description

"Rule and Compass Drawing" PPT Courseware 2

Basic drawing teaching objectives:

⑴ Understand the basic knowledge and steps of ruler and compass drawing.

⑵ Understand the simple application of making an angle equal to a known angle in drawing with ruler and compass.

Preview before class

In geometry, drawing limits using a ruler and compass is called ______.

Among them, the ruler is ______;

The function of the ruler: it can connect a line segment between two points,

And extends to one or both sides, so it can be used as ______, ______, ______.

Function of compass: Take any point as the center of the circle and any length as the radius to draw ______ or ______.

The most basic and commonly used ruler and compass for drawing is called ______.

Some complex ruler and compass drawings are composed of ______.

Two basic drawings:

1. Construct a line segment equal to the known line segment

Known: line segment AB.

Find the construction: line segment A’B’, so that A’B’=AB.

Practice and demonstration:

(1) Make ray A’C’;

(2) Taking point A’ as the center of the circle,

Draw an arc with the length of AB as the radius,

Intersection ray A’C’ at point B’,

A’B’ is the line segment you want to construct.

2. Construct an angle equal to the known angle

Known: AOB (Figure 1)

Ask for: A`O`B`, so that A`O`B`=AOB

Practice and Demonstration

(1) Make ray O′A′:

(2) Take point O as the center of the circle, draw an arc with any length as the radius, intersect OA at point C, and intersect OB at point D;

(3) Take point O′ as the center of the circle, draw an arc with the length of OC as the radius, and intersect O′ A′ at point C′;

(4) Take point C′ as the center of the circle, draw an arc with the CD length as the radius, and intersect the previous arc at point D′;

(5) Draw ray O ′ B ′ through point D ′.

Practice in class:

⑴ Known ∠ AOB, use ruler and compass to calculate

∠ A′O′B′, so that ∠ A′O′B′=2∠ AOB.

⑵ Given the known angles α and β (β＜α＜90°), find an angle to make it equal to α+β.

Homework consolidation

(1) Reading assignment: read through the textbook and review

Consolidate using a ruler and compass to draw an angle equal to the known angle;

(2) Written assignments: P24 Exercise 1.3

No. 1, 2

Keywords: teaching courseware for drawing with ruler and compass, Qingdao edition eighth grade mathematics volume PPT courseware download, eighth grade mathematics slide courseware download, downloading PPT courseware for drawing with ruler and compass, .PPT format;

For more information about the "Rule and Compass Drawing" PPT courseware, please click on the Rule and Compass Drawing ppt tab.

"Construction of Triangular Rules and Compasses" PPT courseware:

"Construction of Triangles with Rulers and Compasses" PPT courseware review introduces the known: AOB, and finds AOB, so that AOB=AOB. Practice and tips: Then AOB is the angle you want to construct. The three sides of the triangle are known. Find the triangle. Known: line segments. Find a, b, c as: △ABC, so that BC=a, AC=b, AB=..

"Rule and Compass Drawing" PPT courseware:

Basic knowledge review of PPT courseware "Rule and Compass Drawing" 1. The tools for ruler and compass drawing are ruler and compass 2. We have already used ruler and compass to draw a line segment equal to a known line segment and an angle equal to a known angle 3. For example Figure, draw the bisector of B, the height on side BC, and the height on side AB..

File Info

Update Time: 2024-11-08

This template belongs to Mathematics courseware Qingdao Edition Eighth Grade Mathematics Volume 1 industry PPT template

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