Question

What is the maximum area of the rectangle formed by bending a wire of length 24cm ?

• A. 36 cm²
• B. 30 cm²
• C. 42 cm²
• D. 46 cm²

Answer 1

Answer:

A. 36 cm²

P=24 2(l+b) = 24 l+b = 24/2 =12 l = x b=12 - x area = lb x(12-x) 12x - x2 differentiate 12 - 2x F'(x) = 0 12-2x=0 12=2x x=12/2=6 length = 6 breadth = 12 - 6 = 6 area = 6x 6 = 36cm²