Farmer grant put a square fence around his vegetable garden to keep the deer from eating corn one side was 10m in length if posts were placed 2m apart how many did he use?

The formula for the perimeter of a square is P = 4s, where P is the perimeter and s is the length of one side.

Since one side of the fence is 10m in length, the perimeter of the fence is:

P = 4 * 10m = 40m

Farmer Grant placed posts 2m apart, so the number of posts he used is:

Number of posts = Perimeter / Distance between posts = 40m / 2m = 20 posts

Therefore, Farmer Grant used 20 posts to put a square fence around his vegetable garden.