Newton's discovery concerning the forces of attraction between objects is called?

1st law
2nd law
3rd law
universal gravitation

It is called Newton's Universal Laws of Gravitation.

We will choose the last option is correct.
Step-by-step explanation:
A land surveyor places two stakes 500 ft apart and locates the midpoint between the stakes.
From the midpoint, he needs to place another stake 100 ft away that is equidistant to the two original stakes.  
Therefore, to apply the Perpendicular Bisector Theorem, the land surveyor would have to identify a line that is "perpendicular to the line connecting the two stakes and going through the midpoint of the two stakes".
Therefore we will choose the last option is correct. (Answer)