A line of symmetry, a basic geometric concept, divides a shape into two identical sections. Teachers introduce the basic concept as early as elementary school, and high school and even college geometry classes employ symmetry. Finding a line of symmetry can be useful in designing objects from greeting cards to landscaping projects.
Things You'll Need
Look for a midpoints in the shape. If you are considering a larger area like a yard, measure the area and draw it to scale on a piece of graph paper to look for midpoints.
Use a ruler to draw a straight line from the estimated midpoint through the shape.
Fold the shape in half to see if both sides match. If they do match, you have found a line of symmetry.
Check all the angles of a shape (if it contains angles) to look for all possible lines of symmetry.
Hold a small mirror perpendicular to a possible line of symmetry. If the shape in the mirror matches the shape on the paper, you have found a correct line of symmetry.
Tips & Warnings
- Some shapes can have multiple lines of symmetry, while some irregular shapes have no lines of symmetry.
- Photo Credit NA/AbleStock.com/Getty Images
How to Find the Line of Symmetry in a Quadratic Equation
Quadratic equations have between one and three terms, one of which always incorporates x^2. When graphed, quadratic equations produce a U-shaped curve...
How to Determine the Symmetry of a Rational Function
The word "symmetry" refers to one half of something being a mirror image of the other half. For example, the capital letter...
What Is the Order of Symmetry?
The order of symmetry can be found almost everywhere in our world. While it may not be immediately noticeable, once you start...
What Is a Mirror Image Across a Line of Symmetry?
A mirror image across a line of symmetry has a very specific name. Find out about a mirror image across a line...