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Wednesday, January 14, 2015

Circular Cylinder Problems, 2

Category: Solid Geometry

"Published in Newark, California, USA"

A straight stairway has a balustrade, with dimensions as shown, containing 2 circular balustrade to a step. The foot and hand rails are parallel. Find the total amount of wood used and the total area to be painted.

Photo by Math Principles in Everyday Life

Solution:

Consider the given figure above

Photo by Math Principles in Everyday Life

A balustrade in a stairway is in a shape of right circular  cylinder. Each step has two balustrades and there are 14 steps in a stairway. Hence, there are 28 balustrades in a stairway. 

The surface area of a right circular cylinder which is a balustrade is




Therefore, the total area of balustrades to be painted is



The volume of a right circular cylinder which is a balustrade is





Therefore, the amount of wood used for balustrades is