Question

Quadrilateral ABDE is a rectangle. DE = 4 in. and BD = 6 in.

If the rectangle is rotated about a line through CF, cylinder Y is created. If the rectangle is rotated about a line through GH, cylinder Z is created.



What is the difference in the measures of the radii of cylinder Y and cylinder Z, in inches?


answer

Answer 1

The answer depends on how, in the absence of the diagram, one draws up the rectangle. The easiest way to draw it up is to make one vertical side AE and the other vertical side BD and with given AB=4 and BD =6, then doing a CF perpendicular to AB and DE then with this as the axis the cylinder is rotated with the radius of 4/2=2 and for the other cylinder, GH which is perpendicular to AE and BD then 6/2=3 so that the difference of the two cylinder radii is 3-2=1. 

Answer 2

If the rectangle ABDE is rotated about the line through CF, cylinder Y is created. The radius of a cylinder is: AB / 2 = 4 / 2 = 2 in. If the rectangle ABDE is rotated about the line through GH, cylinder Z is created. The radius of a cylinder is : DB / 2 = 6 / 2 = 3 in.The difference in the measures of the radii:r 2 - r 1 = 3 in. - 2 in. = 1 in.
Answer: The difference is 1 inch.