Relative error in physics

Question

The length and breadth of a rectangular sheet have been measured by a measuring scale to an accuracy of 0.2m. If the measured values are 35.2cm and 21.7cm respectively, then find the relative errror in area of the sheet

Answer 1

(35.2e^-2 m)(21.7e^-2 m) = 7.6e^-2 m²

Accuracy_length= 0.2 m

Accuracy_area = (0.2 m)² = 4e^-2 m²

Rel. error = | 4e^-2m² - 7.6e^-2m² | / 7.6e^-2m² = 47.9%