Question

the volume of one metre iron rod is 1386 cm cube find its diameter

Answer 1

Given : Volume of rod = 1386 cu cm and height = 1 m or 100 cm

Volume of rod (iron rod is in the shape of cylinder) = πr²h

1386 = 22/7*r²*100

⇒ r² = (1386*7)/2200

⇒ r² = 9702/2200

⇒ r² = 4.41

⇒ r = √4.41

⇒ r = 2.1 cm

Diameter = 2.1 ×2  

Diameter = 4.2 cm

Answer.

Answer 2

Iron Rod Is in Cylindrical Form
Volume=1386cm³
Height or Length=1m or 100cm

Volume of Cylinder=π×radius×height
$\frac{22}{7} \times 100 \times {radius}^{2} = 1386 \\ { radius }^{2} = \frac{1386 \times 7}{22 \times 100} \\ = { radius }^{2} = 4.41\\ = radius = \sqrt{4.41} \\ radius = 2.1 \: cm$
We Know Radius=2.1 cm
Diameter=2.1×2=4.2 cm
=4.2 cm