How to calculate a cross-sectional area

Written by grant d. mckenzie
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to calculate a cross-sectional area
(Calculator image by Alhazm Salemi from Fotolia.com)

When a plane cuts through an object, an area is projected onto the plane. Any plane can be used to cut through the surface, but when that plane is perpendicular to an axis of symmetry, its projection is called a cross-sectional area. For a simple three-dimensional shape, such as a cylinder, the cross-sectional projection is a circle, and the area is easy to calculate. With such shapes as an I-beam, however, calculating the cross-sectional area can be complicated.

Skill level:
Easy

Other People Are Reading

Things you need

  • Calculator (optional)

Show MoreHide

Instructions

  1. 1

    Identify the axis of symmetry. For many applications, this will be the longest axis or the longitudinal axis.

  2. 2

    Identify the shape projected onto a plane that passes through the shape perpendicular to the axis of symmetry. If the shape is complex, divide it into simpler shapes for ease of calculation. An I-beam, for example, can be divided into a horizontal rectangle on the top, a horizontal rectangle on the bottom and a vertical rectangle connecting them in the middle.

  3. 3

    Select the appropriate area formulas to use for the calculation. Some common ones are:

    Triangle: A = 0.5bh

    Rectangle: A = bh

    Circle = (pi)r^2

  4. 4

    Measure the values needed to fill in the formula(s).

  5. 5

    Solve the area equations. For complex geometries, solve the simpler equations and add them together to get the total cross-sectional area.

Don't Miss

Filter:
  • All types
  • Articles
  • Slideshows
  • Videos
Sort:
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the eHow.co.uk site, you consent to the use of cookies. For more information, please see our Cookie policy.