We often compare and contrast things around us. Brand X is better than Brand Y, Actress 1 is more beautiful than Actress 2, Usain Bolt is a faster runner compared to most athletes.

We are also fond of people or things with similarities. We are keen in observing people who look alike, we have a habit of collecting similar things of different colors (or sizes), and we even collect gadgets from a single manufacturer.

Similar things are everywhere. There are cartoon characters that are similar in some ways. Those who do not recognize them would mistake them as family despite their different origins. Buu and Patrick, for example, are like “uncles”, yet Buu was a violent alien, while Patrick has always been an amiable and friendly Starfish.

In mathematics, however, similarity has a quite different meaning. We say that two objects are similar if they are proportional. It means that if we have objects *A* and *B*, and the height of *B* is **twice** that of *A*, then the width of *B* should also be **twice** that of *A *for them to be “mathematically similar.” That implies that every length of every part of *B *should be twice its corresponding part in *A*. Now, this is a very simple concept, but it is very important because it is used in constructing houses, buildings, churches, bridges, and other infrastructures.

Engineers and architects carefully create plans and blueprints of structures before they build them. Modern computers can now be used to render three dimensional plan models. In effect, in building the actual structures, they must be sure that the actual objects are similar to the corresponding object in the plan. Equivalently, engineers have to be sure that the actual structure is similar to its three-dimensional model.

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*Photo Credits*

*Look Alikes by First Time Blogger**Patrick and Buu (Unknown Author)**Dome by Duomo Firenzi*

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