Final answer:
The area of a rectangle is calculated using the formula Area = length × width, which for measurements 12.1 cm and 2.1 cm corresponds to 25.41 cm². The answer should be reported with the same number of significant figures as the measurements, thus option b is correct.
Step-by-step explanation:
The question asks for the area of a rectangle with given length and width measured as 12.1 cm and 2.1 cm respectively. To find the area of a rectangle, the formula is Area = length × width. Multiplying the length and width together:
Area = 12.1 cm × 2.1 cm = 25.41 cm²
However, considering significant figures, since both measurements are given to two decimal places, our final answer must also be reported with the same precision. Consequently, we do not round the result; thus, the area of the rectangular plate is 25.41 cm², which corresponds to option b. It's important to always use the same number of significant figures in the final answer as was used in the measurements.