Question

The length and breadth of a rectangular block are 25.2 cm and 16.8 cm, which have both been measured to an accuracy of 0.1 cm. find the area of the rectangular block.

Answer 1

Area of rectangular block

= 25.2 × 16.8

= 423.4 cm²

∴ \(\frac{\Delta A}{A}=(\frac{\Delta l}{l}+\frac{\Delta b}{b})\)

=\((\frac{0.1}{25.2}+\frac{0.1}{16.8})\)

∴ ΔA = \((\frac{0.1}{25.2}+\frac{0.1}{16.8})\times423.4\)

= 4.2 cm²

∴ Area of rectangle block

= (423.4 ± 4.2) cm²