The length, breadth and thickness of a rectangular
sheet of metal are 4.234 m, 1.005 m and 2.01 cm respectively. Give the area and volume of the sheet to correct significant figures.
Given, length (l) = 4.234 m
Breadth (b) = 1.005 m
Thickness (t) = 2.01 cm = 0.0201 m
Area of sheet (A) = 2(lx b + b x t +t x l)
= 2 [(4.234 x 1.005) + (1.005 x 0.0201)
’ +(0.0201x4.234)]
= 2 x 43604739
= 8.7209478 ${{m}^{2}}$
As thickness has least number of significant figures 3, therefore rounding off area up to three significant figures, we get
Area of sheet (A) = 8.72 ${{m}^{2}}$
Volume of sheet (V) = Ix bx t
= 4.234x1.005 x 0.0201 = 0.0855289
Rounding off up to three significant figures, we get Volume of the sheet = 0.0855${{m}^{3}}$