Respuesta :

Perimeter is the distance around the outside.

A square has 4 equal sides:

Perimeter = 21 x 4 = 84 yards

Answer: Perimeter = 84 yd

Explanation:

Perimeter of square = 4 × side

Side = 21 yd

Perimeter = 4 × 21

= 84 yd

Must click thanks and mark brainliest