If I be the incentre of ∆ ABC and ∠B = 70° and

Home » Aptitude » Plane Geometry » Question

If I be the incentre of ∆ ABC and ∠B = 70° and ∠C = 50°, then the magnitude of ∠BIC is

Firstly , We draw a figure of triangle ABC whose I is incentre ,

Here , ∠B = 70° and ∠C = 50°

∠IBC =	70°	= 35° ;
	2

∠ICB =	50°	= 25° ;
	2

We know that , ∠BIC + ∠ICB + ∠IBC = 180°
∴ ∠BIC = 180° – 35° – 25°
∠BIC = 180° – 60° = 120°