Answer:
108 cm²
Step-by-step explanation:
Area of a rectangle, A = length, l × width, w
Perimeter of a rectangle = (2 × length) + (2 × width)
42 cm = 2l + 2w
but length = w + 3cm
42 cm = 2(w + 3cm) + 2w
42 cm = 2w + 6cm + 2w
42 cm = 6cm + 4w
4w = (42 - 6) cm
4w = 36 cm
》w = 9cm
》l = w + 3cm = 9cm + 3cm
l = 12 cm
Area = 12 × 9 = 108 cm²
