Please help with part A, I’re tried the question but I’m not sure if it’s correct

Answer:
tsa of semi-cylinder is 21.21m²
Step-by-step explanation:
tsa of cylinder = 2πr² + 2πrh
radius = diameter ÷2
= 1.5m
tsa = (2×π×1.5²) + (2×π×1.5×3)
= 4.5π + 9π
= 13.5π
≈ 42.412m²(3d.p) (cylinder)
semi = 42.41 ÷ 2
≈ 21.21m² (2d.p)
(Correct me if i am wrong)
V = Ab·h/2
= π·r²·h/2
r = d/2 = 3m/2 = 1,5m
= π·(1,5m)²·3m/2
= π·2,25m²·1,5m
= 3,375π m³
= 10, 5975 m³
π = 3,14