A rectangular plate has a length of (21.3\pm0.2) cm and a
width of (9.80\pm 0.1) cm. Find the area of the plate and the
uncertainty in the calculated area.
Solution
Area = lw = (21.3\pm0.2 cm) X (9.80\pm0.1 cm)
\cong(21.3 X 9.80 \pm 21.3 X 0.1 \pm 0.2 X 9.80) cm^2...