You entered 3 sides of a triangle.
Find the 3 angles using SSS method.
We need to check the largest angle first.
See if we have an obtuse angle
This is Side 1 Using Law of Cosines:
Find Angle 1 Using Law of Cosines
Take Arccosine of the following:| Angle 1 = | Side 22 + Side 32 - Side 12 |
| 2 * Side 2 * Side 3 |
| Angle 1 = | 8.48532 + 6.32462 - 122 |
| 2 * 8.4853 * 6.3246 |
| Angle 1 = | 72.00031609 + 40.00056516 - 144 |
| 107.33225676 |
| Angle 1 = | -31.99911875 |
| 107.33225676 |
Angle 1 = Arccos(-0.29813142587276)
Angle 1 = 107.345°
Find Angle 3 Using Law of Cosines
Take Arccosine of the following:| Angle 3 = | Side 12 + Side 22 - Side 32 |
| 2 * Side 1 * Side 2 |
| Angle 3 = | 122 + 8.48532 - 6.32462 |
| 2 * 12 * 8.4853 |
| Angle 3 = | 144 + 72.00031609 - 40.00056516 |
| 203.6472 |
| Angle 3 = | 175.99975093 |
| 203.6472 |
Angle 3 = Arccos(0.86423850133957)
Angle 3 = 30.204°
Now solve for Angle 2
The sum of angles n a triangle = 180
Missing Angle = 180 - sum of 2 angles
Angle 2 = 180 - (Angle1 + Angle 3)
Angle 2 = 180 - (107.34540674467 + 30.20413451409)
Angle 2 = 180 - 137.54954125876
Angle 2 = 42.45°
