Monday, April 19, 2010

Area

Today, we took our Geometry Formulas Gateway. When I was studying for it before class, it seemed a little overwhelming to try and memorize all of the formulas. Most of the time, I found it easier to break up a figure into several parts to try and calculate its area or volume. Personally, I think it is easy to find the perimeter of a figure. All that you need to do is add up the lengths of each side. The perimeter of a circle, however, is just finding the circumference.

Finding the area of a rectangle and square are easy. All you have to do is multiply length and width to get the area. Calculating the area of a parallelogram is easy to understand when it is broken up. The picture below explains the process.
A trapezoid is a little different. An easier way to look at finding the area is duplicating the trapezoid and then rotating it to make a parallelogram as the picture shows below. Since you only need the area of one trapezoid, you multiply the area of the parallelogram that you formed by 1/2 to give you the area of just one.
Finding the area of a triangle can be easier understood if you duplicate it and then fit it together with the other to form a parallelogram. It is basically the same concept used to find the area of a trapezoid as discussed above. If you are trying to find the area of a right triangle, duplicating it and then fitting it together with the other will form a rectangle.
The easiest way to find the area of a circle is to just memorize the formula.
I found a website that goes over area formulas that may also be of some help.

3 comments:

  1. Haha, I wish we wouldn't have waited to figure this stuff out until right before the gateway!! Hopefully we'll both do better on the retakes (if we need them)! :)

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  2. Thanks. Hopefully I can pass my retake haha.

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  3. Very nice summary. I hadn't seen that particular way to explain the area of a trapezoid. Nice find. :)

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