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What is the perimeter of the hexagon?

A hard-level "Length" problem.3.14 is not a number to memorise — it was squeezed out. The inscribed hexagon shows π > 3; a circumscribed square shows π < 4. More sides, more accuracy.

GivenA regular hexagon fits exactly inside a circle of radius 6 cm / π = 3.14

Length ★★★★☆☆ What is the perimeter of the hexagon? 6cm ? cm

Hints

  1. Draw lines from the centre to the six corners: the hexagon splits into six triangles.
  2. Take one of them. The two sides from the centre are both radii, so they are equal — and the angle at the centre is 360 ÷ 6 = 60°.
  3. Two equal sides with 60° between them make an equilateral triangle, so the third side is also 6 cm — the same as the radius.
  4. All six sides equal the radius, so the perimeter is 6 × 6 = 36 cm.
  5. One last thing, and it matters. The hexagon lies inside the circle, so its perimeter must be shorter than the circumference. And 36 is exactly 3 × the diameter (12 cm). So diameter × 3 &lt; circumference — which is a proof that π is bigger than 3.

Answer 36cm

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