Answer:
840 cm
Step-by-step explanation:
Given that in the question we have, : 9, 1 cm × 1 cm squares setting a 3 × 3 grid.
Therefore wire required in 3 x 3 grid is
3(3+1) + 3(3+1)
= 3 × 4 + 3 × 4
= 24 I'm
Similarly, the length of the wire required in 20 by 20 grid will be
=> 20(20+1) + 20(20+1)
=> 20 × 21 + 20 × 21
=> 420 + 420
= 840cm
