"Positional Relationship between Points and Circles" PPT

Description

"Positional Relationship between Points and Circles" PPT

Part One: Observation

Our country's shooting athletes have won gold medals repeatedly in the Olympic Games and won honors for our country. The picture on the right is a schematic diagram of a shooting target. It is composed of many concentric circles (circles with the same center and different radii). You know how to hit different positions on the target. How are grades calculated?

question inquiry

Question 1: Observe the positional relationship between point A, point B, point C and the circle in the picture?

Point A is inside the circle,

Point B is on the circle,

Point C is outside the circle.

Question 2: Assume the radius of ⊙O is r, tell the relationship between the distance and radius between point A, point B, point C and the center O:

OA < r, OB = r, OC > r.

The positional relationship between points and circles PPT, the second part of the content: the positional relationship between points and circles

Let the radius of ⊙O be r, and the distance from the point to the center of the circle be d. but

Point P is in the circle ←→d＜r;

Point P is on the circle ←→d = r;

Point P is outside the circle ←→d> r.

Exercise: It is known that the radius of the circle is equal to 5 cm, and the distance from the point to the center of the circle is:

A. 8 cm B. 4 cm C. 5 cm.

Please tell us the positional relationship between the point and the circle respectively.

The positional relationship between points and circles PPT, the third part: typical examples

For example: As shown in the figure, the sides of the rectangle ABCD are AB=3 cm and AD=4 cm.

(1) Take point A as the center and 3 cm as the radius to construct a circle A. What is the positional relationship between points B, C, D and circle A?

(2) Take point A as the center and 4 cm as the radius to construct a circle A. What is the positional relationship between points B, C, D and circle A?

(3) Take point A as the center and 5 cm as the radius to construct a circle A. What is the positional relationship between points B, C, D and circle A?

Example 1, as shown in the figure, it is known that the sides of the rectangle ABCD are AB=3 cm and AD=4 cm.

(1) Take point A as the center and 4 cm as the radius to construct a circle A. What is the positional relationship between points B, C, D and circle A?

(2) If a circle A is constructed with point A as the center, so that at least one point among the three points B, C, and D is inside the circle, and at least one point is outside the circle, then the range of the radius r of circle A is What?

The positional relationship between points and circles PPT, part 4 content: ability improvement

1. The radius of ⊙O is r=10cm, the distance from the center of the circle to the straight line L is OM=8cm, there is a point P on the straight line L, PM=6cm, then point P ( )

A is inside ⊙O B is outside ⊙O

C on ⊙O D cannot be determined

2. The radius of ⊙O is 6, the coordinates of the center O are (0, 0), and the coordinates of point P are (4, 5), then the positional relationship between point P and ⊙O is ( )

A is inside ⊙O B is outside ⊙O

C is on ⊙O D is on ⊙O or within ⊙O

3. The distance between point P and the nearest point on the definite circle is 4cm, and the distance between the farthest point is 9cm. Then the radius of the circle is ( )

A 2.5cm B 6.5cm

C 2.5cm or 6.5cm D 13cm

Keywords: Free download of mathematics PPT courseware for the second volume of the ninth grade of Hebei Education Edition, PPT download of the positional relationship between points and circles, .PPT format;

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Update Time: 2024-10-20

This template belongs to Mathematics courseware Hebei Education Edition Ninth Grade Mathematics Volume 2 industry PPT template

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