Pragya wrapped a cord around a circular pipe of radius 4 cm (adjoining figure) and cut off the length required of the cord. Then she wrapped it around a square box of side 4 cm (also shown). Did she have any cord left?
It is given in the question that,
Side of square = 4 cm
We know that,
Perimeter of square = 4 × Side
= 4 × 4
= 16 cm
Also, it is given that:
Radius of circular pipe = 4 cm
∴ Perimeter of circular pipe = 2
r
= 2 × 3.14 × 4
= 25.12 cm
Hence,
Length of the chord left with Pragya = 25.12 – 16
= 9.12 cm
9