1 / 13

# 球 内切外接问题 - PowerPoint PPT Presentation

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## 球 内切外接问题

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

1、若球的大圆面积扩大为原来的 2 倍，则

2、两个半径为 1 的铁球，熔化后成铸成一

A. B. C. D.

A

C

O

A1

C1

C

A

C

O

A1

C1

A1

C1

A

O

C

A

A

O

O

E

B

O1

E

B

O1

O1是正△BCD的中心，且AE 为斜高

1

A

A

1

F

O

O

E

B

O1

E

B

O1

∵ Rt △ AFO ∽ Rt △ AO1E

A

1

θ

O

E

B

O1

A

O

D

B

C

VO-ABC + VO- ABD + VO-ACD + VO-BCD

A

5

6

5

O

D

6

5

B

E

5

C

∵ AC = AD = BC = BD，

∴ CD ⊥ AE ，CD ⊥ BE，

∵AE∩BE = E，

∴CD ⊥ 面ABE

∵ AD = BD = 5，DE = 3

∴ AE = BE = 4

A

5

6

5

O

D

6

5

B

E

5

C

∵ 各侧面全等

P

G

O

D

A

O1

E

∵ Rt △ PGO ∽ Rt △ PO1D

P

A

C

O

∵ PA = PC = a

∴ △ PAC 是等腰 Rt △