Using that side, find the perimeter of the square

1. 1
   Perimeter of a square $=4L$.
2. 2
   Using the unrounded side ($L\approx 16.24$) before rounding the final answer: $4\times 16.24=64.96$.

✅ Answer: ≈ 65.0 cm (3 s.f.)

Using that radius, find the area of the circle

1. 1
   Area $=\pi r^2=\frac{22}{7}\times (21.6{)}^2$
2. 2
   $21.6^2=466.56$, so area $=\frac{22}{7}\times 466.56=\frac{10264.32}{7}\approx 1466.3$

✅ Answer: ≈ 1470 m² (3 s.f.)

And the other direction: if one side of a cube is 12 m, find its volume

1. 1
   $V=L^3=12^3$
2. 2
   $12\times 12=144$, then $144\times 12=1728$

✅ Answer: $V=1728m^3$