For students who are taking Geometry, one of the most dreaded areas of study is perimeter and having to learn the various Perimeter Formulas that accompany it. However, learning these formulas is actually the easiest part of Geometry. Students who memorize the formulas given to them will always have the keys to solving the problem correctly right at their fingertips. Formulas, then, should be thought of as a blessing. They basically spell out how to solve any problem that there is. It’s just up to the student to understand each formula and to memorize them correctly. Fortunately, most of them can be explained quite easily.

Each Geometry formula for perimeter is based on what shape the problem focuses on. So, Perimeter Formulas vary depending on the shape in question. The formula to find a Square Perimeter, for example, is different from the formula for a Rectangle Perimeter and on and on. One important and helpful rule to remember is that the perimeter of any polygon will always be equal to each of the sides added together. In the case of a Square Perimeter problem, the answer would be arrived at by adding each side of the square or by multiplying a side of the square by four. This problem is simple, because each of the sides are equal. When this is not the case, things can get quite a bit more complex.

Remember, that in Geometry, Perimeter Formulas are always based on shape, so this should be the very first thing a student focuses on. Before even picking up a pencil, the student must determine what shape the problem is referencing. For those problems that ask for a Rectangle Perimeter, students must always use the following formula: two multiplied by one side, usually represented as a, added to two multiplied by the other side, usually represented as b. Most commonly, this is written simply as 2a   2b in many textbooks.

Another important Geometry formula to learn is for Circle Perimeter. Many people find Circle Perimeter problems to be a bit tricky, but they are actually fairly simple if one knows the formula. It is simply the numeral two multiplied by pi multiplied by the radius of the circle. When the radius of the circle is unknown, the student must solve for it. Also, pi is most commonly expressed as either 3.14 or 3.142 depending on the particular problem and the preference of the instructor. The final type of problem to discuss is a Triangle Perimeter problem. To find Triangle Perimeter, student simply add each side together. Since triangles have three sides, this is commonly expressed simply as a   b   c. Memorizing these formulas will make solving such problems much easier.