In ΔDEF, ∠D = 60°, ∠E = 70° and the bisectors of ∠E and ∠F meet at O. Find (i) ∠F (ii) ∠EOF.
(i) ∠F = 50°, (ii) ∠EOF = 120°
∠F = 180 − (60+70) = 50°. At incenter, ∠EOF = 90° + (∠D/2) = 90° + 30° = 120°.