What is a reasonable estimate of the perimeter of the base that is a square with all 4 sides 143.5 meters,

4 * 145 = 580m.

Which is a reasonable estimate of the perimeter of this triangle?

To find the perimeter of a square, you can simply multiply the length of one side by 4, since all four sides of a square are equal in length.

In this case, the length of each side of the square is given as 143.5 meters. To estimate the perimeter, you multiply this length by 4:

Perimeter = 143.5 meters × 4 = 574 meters

Therefore, a reasonable estimate of the perimeter of the square base is approximately 574 meters.