3. 36 unit squares are joined to form a rectangle with the least perimeter. Perimeter of the rectangle is
(a) 12 units
(b) 26 units
(c) 24 units
(d) 36 units
Area = 36. Factors close to a square: 6 × 6 = 36.
But we need least perimeter rectangle, so choose 9 × 4.
Perimeter = 2(9 + 4) = 26 units.