Let the length and breadth of the board be l and b respectively.
Given: Length = 24 cm
and area of the board = 192 cm2 ...(1 Mark)
Area =l×b=24×b=192
⇒24b=192
⇒b=8 cm ...(1 Mark)
Perimeter =2(l+b)=2(24+8)
=2×32=64 cm ...(1 Mark)