Question

( angle mathrm{ABC}=60^{circ}, mathrm{ACB}=50^{circ} )
( angle mathrm{IBC}=frac{1}{2} angle mathrm{ABC}=30^{circ} )
( angle mathrm{ICB}=frac{1}{2} angle mathrm{ACB}=25^{circ} )
( therefore angle B I C=180^{circ}-30^{circ}-25^{circ}=125^{circ} )

# Ex.4. I is the incentre of A ABC, ZABC = 60° and ZACB = 50°. Then Z BIC is : (1) 55° (2) 125° (3) 70° (4) 65°

Solution