The sides of a rectangle are (10.5 ± 0.2) cm and (5.2 ± 0.1) cm. Calculate its perimeter with error limits

[prasanna]

l = (10.5 ±0.2) cm, b = (5.2 ±01) cm
Perimeter of a rectangle, p = 2 (l + b)
= 2 (10.5 + 5.2) = 31.4 cm
∆p = ±2(∆l + ∆b)
= ± 2 (0.2 + 01) = ±0.6
Perimeter of a rectangle = (31.4 ± 06) cm