Some of the practical applications of the Pythagorean theorem include marine navigation, building almost anything (houses, bridges etc.) and figuring out which TV-size to choose (sizes are given as diagonals, so you don’t know the hight and width).
Let’s learn the theory about Pythagorean Theorem:
Exercises
Here are some excellent online exercises of the Pythagorean theorem:
https://www.shmoop.com/squares-square-roots/pythagorean-theorem-exercises.html