| ( | 180 | − | ( | 180 | − | x | ) | ) | ÷ | 2 | + | 2 | ( | 180 | − | 2 | x | ) | = | 180 |
| Left side of the equation = | 180 | × | 1 2 | − | ( | 180 | − | x | ) | × | 1 2 | + | 2 | ( | 180 | − | 2 | x | ) |
| = | 90 | − | ( | 180 | − | x | ) | × | 1 2 | + | 2 | ( | 180 | − | 2 | x | ) |
| = | 90 | − | 180 | × | 1 2 | + | x | × | 1 2 | + | 2 | ( | 180 | − | 2 | x | ) |
| = | 90 | − | 90 | + | x | × | 1 2 | + | 2 | ( | 180 | − | 2 | x | ) |
| = | 0 | + | 1 2 | x | + | 2 | ( | 180 | − | 2 | x | ) |
| = | 0 | + | 1 2 | x | + | 2 | × | 180 | − | 2 | × | 2 | x |
| = | 0 | + | 1 2 | x | + | 360 | − | 4 | x |
| = | 360 | − | 7 2 | x |
| 360 | − | 7 2 | x | = | 180 |
| - | 7 2 | x | = | 180 | − | 360 |
| - | 7 2 | x | = | - | 180 |
| 180 | = | 7 2 | x |
7 2 | x | = | 180 |
| x | = | 180 | ÷ | 7 2 |
| = | 180 | × | 2 7 |
| x | = | 360 7 |
| x | = | 51.428571 |