Question

The inner and outer radii of a cylindrical pipe are 4 cm and 5 cm respectively find the area of crosssection of the pipe

Answer 1

since inner radius can't be greater than outer radius. so taking inner raddii as 4 cm and outer raddii as 5 cm
Inner radius of cylindrical pipe; r = 4 cm
Inner radius of cylindrical pipe; R = 5 cm
Since the cross-section of cylindrical pipe is circular.
So area of cross-section of pipe =
π(R^2−r^2) = 22/7(5^2−4^2) = 22/7×9 = 28.285 cm^2__ANSWER..!!!