Chapter 4.6, Problem 81E

To determine

a)

To prove that

\ $\text{Δ}\text{PNB}\text{and Δ PNC}$ are congruent.

To determine

b)

To prove that $\text{APB}\text{and}\text{APC}$ having equal length

To determine

c)

To prove the similarity of $\text{AQB and}\text{AQC}$ having equal length.

To determine

d)

To find the path $\text{APC}$ is shorter than $\text{AQC}$.