InterviewSolution
Saved Bookmarks
| 1. |
In ` A B C ,`let `L ,M ,N`be the feet of the altitudes. The prove that `sin(/_M L N)+sin(/_L M N)+sin(/_M N L)=4sinAsinBsinC` |
|
Answer» Using properties of pedal triangle, we have `angle MLN = 180^(@) - 2A` `angle LMN = 180^(@) - 2B` `anlge MNL = 180^(@) - 2C` `rArr sin (angle MLN) + sin (angle LMN) + sin (angle MNL)` `= sin 2A + sin 2B + sin 2C` `= 4 sin A sin B sin C` |
|