Let Length = 20 and breadth =10 , then permitter = 2(L+w) = 60 Length changed 15% of 20 is 3 ⇒20+3=23 (new length) Breadth changed 10% of 10 is 1 ⇒ 10-1=9 (new breadth) Original perimeter =2×30=60 unit New perimeter =2×32=64 unit Change in Perimeter is 64-60= 4 % changed =