(1)证明:∵∠ABC=∠APC=60°,又
![]() |
| AB |
![]() |
| AC |
∴∠ACB=∠ABC=60°
∴△ABC为等边三角形;
(2)连接OC,过点O作OD⊥BC,垂足为D,
∵△ABC为等边三角形,点O△ABC的内心,
∴OC是∠ACB的平分线,
∴∠OCD=30°,
在Rt△ODC中,DC=2,∠OCD=30°,
∴OC=
| DC |
| cos30° |
| 2 | ||||
|
| 4 | ||
|
4
| ||
| 3 |
∴S⊙O=π•OC2=
| 16 |
| 3 |
![]() |
| AB |
![]() |
| AC |

(1)证明:∵∠ABC=∠APC=60°,![]() |
| AB |
![]() |
| AC |
| DC |
| cos30° |
| 2 | ||||
|
| 4 | ||
|
4
| ||
| 3 |
| 16 |
| 3 |