Question

In trianglePQR, the bisector of angleQ and angleR intersect at I. if angle P=70,then find m angleQIR​

Answer 1

in ∆ PQR

angle p+angle Q+angle R=180°(angle sum property)

70+angle Q+angle R=180°

angle Q+angle R=180°-70°

=110°

now,in ∆QIR

1/2 angleQ +1/2 angle R+angle QIR=180°(angle sum property of a∆)

1/2(angle Q+ angle R)+angle QIR=180°

1/2(110°)+ angle QIR=180°

55°+angle QIR=180°

angle QIR=180°-55°

angle QIR=125°

hope it helps