Question

triangle ABC the bisector of Angle B and angle C intersect at i if angle A is equal to 70 degree then find angle b i c​

Answer 1

In triangle ABC

Using Angle Sum Property, angleA + angleB + angleC = 180

Since angleA = 70, angleB + angleC = 110 →(i)

In triangle BOC

Using Angle Sum Property, angleBOC + angleOCB + angleOBC = 180

angleBOC + 1/2angleC + 1/2angleB = 180

angleBOC + 1/2(angleC + angleB) = 180

angleBOC + 1/2(110) = 180

angleBOC = 180-55

angleBOC = 125

Alter method: Using Corrolary of Angle Sum Property

angleBIC = 90 + 1/2angleA

angleBIC = 90 + 35

angleBIC = 125