A lattice point is a point whose coordinates are integers

lattice-point
coordinates-integers

#1

A lattice point is a point whose coordinates are integers.

Is it possible to form a square whose area is 18 by connecting four lattice points? Explain.

Asnwer:

No. If a square has an area of 18, then one of it’s sides must have length of 18−−√. Since this number is not an integer, you cannot connect lattice points to get this length.