You might ask”What is the Pyhtagorean Theorem???” Well, it is the formula applied for a right-angled triangle(triangle with a 90 degrees side). The formula is a^2+b^2=c^2. It means that the 2 legs of a triangle, each squared(or multiplied by the same number) and then added, will be the squared measurement of the hypotenuse. To give you a better idea, here is a picture.

Here is a sample question:

If the legs of a triangle are 3 and 4, respectively, then what is the hypotenuse?

Answer: 5

Solution: 3^2+4^2=25

1×1=1  wrong

2×2=4 wrong

3×3=9 wrong

4×4=16 wrong

5×5=25 correct!!!!

Now, here is the problem I presented.

Two ships leave port at the same time. Ship X is heading due north and Ship Y is heading due east. Ten hours later they are 500 miles apart. If the Ship X had traveled 400 miles from the port, how many miles had Ship Y traveled?