Dimensions of the rectangle (width and length) are 19 cm and 31 cm respectively.
Step-by-step explanation:
Perimeter of a rectangle = 2(length + width)
100 = 2(x + 12 + x)
100 = 4x + 24
4x = 100 - 24 = 76
∴ x = 76/4 = 19 cm
∴ Length = 19 + 12 = 31 cm