If $YM,ZM$ are internal bisectors and $YN,ZN$ external bisectors of $\angle Y,\angle Z$ of a triangle, then $\angle MYZ

Question

If $YM,ZM$ are internal bisectors and $YN,ZN$ external bisectors of $\angle Y,\angle Z$ of a triangle, then $\angle MYZ + \angle NYZ$ equals—

Accepted Answer

$90^{\circ}$

Answer

$45^{\circ}$

Answer

$60^{\circ}$

Answer

$180^{\circ}$

If YM,ZMYM,ZMYM,ZM are internal bisectors and YN,ZNYN,ZNYN,ZN external bisectors of ∠Y,∠Z\angle Y,\angle Z∠Y,∠Z of a triangle, then ∠MYZ+∠NYZ\angle MYZ + \angle NYZ∠MYZ+∠NYZ equals—