Concept:When two shapes have the same perimeter, equate their perimeters and then find the required area.Solution:Perimeter of a rectangle =2(length+breadth).Given length =10 cm and breadth =6 cm.So, perimeter of the rectangle =2(10+6)=2×16=32 cm.The square has the same perimeter, so its perimeter is also 32 cm.Let the side of the square be s.Perimeter of a square =4s.Thus, 4s=32.Dividing both sides by 4: s=432=8 cm.Area of the square =s2=82=64 cm2.Answer:Option D (64 cm2)