| sinA |
| cosC |
| sinA |
| sinC |
因为0＜A＜π，0＜C＜π．
所以sinA＞0．从而sinC=cosC．
又cosC≠0，所以tanC=1，则C＝
| π |
| 4 |
（Ⅱ）由（Ⅰ）知B=
| 3π |
| 4 |
于是
| 3 |
| π |
| 4 |
| 3 |
| 3 |
| π |
| 6 |
因为0＜A＜
| 3π |
| 4 |
| π |
| 6 |
| π |
| 6 |
| 11π |
| 12 |
所以当A+
| π |
| 6 |
| π |
| 2 |
| π |
| 3 |
| π |
| 6 |
综上所述，
| 3 |
| π |
| 4 |
| π |
| 3 |
| sinA |
| cosC |
| a |
| c |
| 3 |
| π |
| 4 |
| sinA |
| cosC |
| sinA |
| sinC |
| π |
| 4 |
| 3π |
| 4 |
| 3 |
| π |
| 4 |
| 3 |
| 3 |
| π |
| 6 |
| 3π |
| 4 |
| π |
| 6 |
| π |
| 6 |
| 11π |
| 12 |
| π |
| 6 |
| π |
| 2 |
| π |
| 3 |
| π |
| 6 |
| 3 |
| π |
| 4 |
| π |
| 3 |