A square pyramid has 4 triangles and the square base.
Calculate the area of one triangle, multiply that by 4 then add the area of the base.
Area of triangle = 1/2 x base x height = 1/2 x 5 x 12 = 30 square yards.
30 x 4 = 120 square yards
Area of base = 5 x 5 = 25 square yards
Total = 120 + 25 = 145 square yards.