South and then east

William walks 16 m south from his house and turns east to walk 63 m to reach his friend's house. While returning, he walks diagonally from his friend's house to reach back to his house. What distance did he walk while returning?

Correct answer:

c =  65 m

Step-by-step explanation:

$$\begin{gathered} a=16\text{m} \\ b=63\text{m} \\ {c}^2=a^2+b^2 \\ c=\sqrt{a^2+b^2}=\sqrt{16^2+63^2}=65\text{m} \end{gathered}$$

Try another example