| A | ∠2>∠4 |
| B | ∠2<∠4 |
| C | ∠2=∠4 |
| D | ∠2与∠4大小不确定 |
| A | 若∠1+∠2+∠3=180°,则∠1、∠2、∠3互补 |
| B | 若∠1+∠2=90°,则∠1与∠2互余 |
| C | 若∠1+∠2=180°,则∠1与∠2互余 |
| D | 一个角的余角和它的补角相等 |
| A | ∠α=∠β |
| B | ∠β=∠γ |
| C | ∠α=∠β=∠γ |
| D | ∠α=∠γ |
| A | 25°,65° |
| B | 20°,70° |
| C | 35°,45° |
| D | 15°,75° |
| A | 38° |
| B | 38°17′ |
| C | 30°37′ |
| D | 38°37′ |