The green square is 15 ft wide by 15 ft tall.
The area of one green square is 15 x 15 = 225 square feet.
There are 4 sides plus the base : 225 x 5 = 1125 square feet for the green part.
One triangle has a base 15 feet wide and a height of 9 feet.
The area for one triangle is 1/2 x 15 x 9 = 67.5 square feet.
There are 4 triangles: 67.5 x 4 = 270 square feet.
Total: 1125 + 270 = 1,395 square feet.