Question

please answer my question

Answer 1

(i)
area = 6.16m²
π = 3.14 (constant)
Area = π×r²
6.16 = 3.14r²
r² = 6.16/3.14
√r² = √1.96
r = 1.4m
Diameter = 2×r
= 2×1.4
= 2.8m
Circumference = π × d
= 3.14 × 2.8
= 8.792m

(ii)
area = 394.24 cm²
π = 3.14 (constant)
Area = π×r²
394.24 = 3.14r²
r² = 394.24/3.14
√r² = √125.5
r = 11.20cm
Diameter = 2 × r
= 2 × 11.29
= 22.4cm
Circumference = π × d
= 3.14 × 22.4
= 70.34cm

(iii)
area = 25π cm² = 78.5cm²
π = 3.14 (constant)
Area = πr²
78.5 = 3.14r²
r² = 78.5/3.14
√r² = √25
r = 5cm
Diameter = 2r
= 2×5 = 10cm
Circumference = πd
= 3.14 × 10 = 31.4cm