"Angle of Circle" PPT Courseware 2

Description

"Angle of Circle" PPT Courseware 2

life practice

When a player shoots at B, D, and E, his position forms three opening angles to goal AC: ∠ABC, ∠ADC, and ∠AEC. What is the relationship between the sizes of these three angles?

What is the relationship between the size of the circumferential angle subtended by AC ∠ AEC ∠ ABC ∠ ADC?

What patterns can you spot?

Instant testing (2)

As shown in the figure, points A, B, C, and D are on the same circle. The diagonals of the quadrilateral ABCD divide the four interior angles into eight angles. Which of these angles are equal?

New knowledge exploration

As shown in the figure, ∠C=∠G in the circle, then what is the relationship between the size of AB and AB? Why?

prove:

Connect OA, OB, OC, OD

∵∠C=1/2∠AOB

∠G=1/2∠EOF

∠C=∠G

∴∠AOB=∠EOF

∴AB=EF

Instant testing (3)

1. As shown in the figure, in ⊙O, ∠BOC=50°, then ∠A=_ °

2. As shown in the figure, AB is the diameter, then ∠ACB=______ ∠AC`B=_______.

What conclusion can you draw?

Instant testing (4)

(1) As shown in the figure, ∠DCB=120° then ∠AOB=______°

(2) As shown in the figure, the diameter of ⊙O is AB=10cm, C is a point on ⊙O, ∠BAC=30°, then BC=____cm

summary

1. What knowledge did we learn in this lesson?

2. What methods have we learned in this lesson?

Circumferential angle work:

Required questions: 2 questions on page 87 of the textbook

Optional questions: 3 questions on page 87 of the textbook

After-school development

As shown in the figure, it is known that the three vertices of �ABC are all on ⊙O, AD is the height of �ABC, and AE is the diameter of ⊙O.

Prove that ∠BAE=∠CAD

Keywords: Circumference and angle teaching courseware, Qingdao edition ninth grade mathematics volume PPT courseware download, ninth grade mathematics slide courseware download, circumference and angle PPT courseware download, .PPT format;

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"Central Angle and Circumferential Angle" PPT courseware 3:

"Central Angle and Circumferential Angle" PPT Courseware 3 1. The angle of a circle subtended by the same arc is ________. 2. A quadrilateral with four vertices on the same circle is called __________. This circle is called _____________. The circle inscribes the opposite angle of the quadrilateral _______. 1. (3 points) Next...

"Central Angle and Circumferential Angle" PPT courseware 2:

"Central Angle and Circumferential Angle" PPT Courseware 2 1. The angle where the vertex is on the circle and both sides are _________ with the circle is called _________. 2. The circumferential angle subtended by an arc on a circle is equal to the ________ of the central angle subtended by it. 3． The angle of the circle subtended by the semicircle (or diameter) is______..

"Central Angle and Circumferential Angle" PPT courseware:

"Central Angle and Circumferential Angle" PPT courseware 1. The angle whose vertex is at the center of the circle is called ________. 2. In the same circle or equal circles, the chords subtended by equal central angles _________, and the arcs subtended by equal chords or equal arcs also ________; the central angles subtended by equal chords or equal arcs _________. 1..

File Info

Update Time: 2024-10-19

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

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