Question

In parallelogram ABCD, the interrior bisectors of the consecutive angles B and C intersect at P. Find ∠BPC.

Answer 1

Let BP as x-axis and BY as y-axis.

Let i and j be unit vectors along x-axis and y-axis, respectively.

Here,

Let θ the angle between BP and CP

Now,

Therefore, the angle between the angle bisectors of angles B and C is 90°.