| A | 61° |
| B | 60° |
| C | 37° |
| D | 39° |
| A | ∠1+∠0=∠A+∠2 |
| B | ∠1+∠2+∠A+∠O=180° |
| C | ∠1+∠2+∠A+∠O=360° |
| D | ∠1+∠2+∠A=∠O |
| A | (1)(2)(3) |
| B | (1)(2)(3) |
| C | (1)(3)(4) |
| D | (1)(2)(3)(4) |
| A | 150° |
| B | 300° |
| C | 450° |
| D | 600° |
| A | 150° |
| B | 210° |
| C | 240° |
| D | 270° |