Add the half circle to the rectangle and subtract the triangle.
Area of half circle = 1/2 x pi x 8.5^2 = 113.4325
Area of rectangle = 11 x 17 = 187
Area of triangle: 1/2 x 3 x 17 = 25.5
Total area: 113.4325 + 187 - 25.5 = 274.9325 square m
Perimeter: outside dimension for 1/2 circle = 1/2 x 3.14 x 17 = 26.69
Perimeter = 26.69 + 11 + 11 + 9 + 9 = 66.69 m