Diameter = 8 yards so the Radius = 4 yards:
Area of a sphere = 4π.R² and hemisphere = 2π.R²
Area of hemisphere = 2.π.(4)² = 32.π
But note we didn't calculate yet the are that closes this hemisphere:
Area of the cicle = π.R² = π.(4)² = 16.π, so the surface area of the hemisphere is 32π + 16π = 48.π (Or =150.8 yard²)
