Geometry Practice Test 1

I is the incentre of ΔABC
BI and CI is the bisector of ∠B and ∠C
So, ∠ABC = 60°, ∠BCA = 80
∠IBC = 30º ∠ICB = 40º
In ∠BIC ,

∠IBC+∠ICB+∠BIC = 180°
30° + 40° +∠BIC = 180°
∠BIC = 180° − 70°
∠BIC = 110°