Question

To get to his parent's house, Isaiah would have to drive due north 9 kilometers. To get to his grandparents' house, he would have to drive due east 12 kilometers. The straight-line distance between the parents' and grandparents' houses is __ kilometers.

Answer 1

let us represent the question with a diagram for better understanding.

Using Pythagoras theorem

$\begin{gathered} c^2=12^2+9^2 \\ c^2=144+81 \\ c=\sqrt[\square]{225} \\ c=15\text{ km} \end{gathered}$

The distance between the parents and grandparent house = 15 km