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How to Do Pre Algebra Geometric Figures

At the end of a pre-algebra course, students may begin to learn fundamentals of geometry to prepare for that higher-level class. The basic concepts of perimeter and area are taught using polygons, which are closed figures with straight line segments as sides. Rectangles and squares are the most common polygons. Students also learn the formulas to determine the circumference and area of a circle. You should know that the circumference of a circle is essentially its perimeter, or the distance around the circle. It is calculated using the diameter, which is the straight-line distance from one side of the circle to the other.

Instructions

- 1
  Calculate the perimeter of a polygon by adding up the length of each side. Find the perimeter of a shape whose sides are equal in length, such as a rectangle or square, by multiplying the side length by the number of sides it applies to: for example, a rectangle with a short side of 4 and a long side of 8 could be written 2(4) + 2(8) = 8 + 16 = 24, while a square with sides of 4 would be 4(4) = 16. If none of the sides are equal, just add each side individually.
- 2
  Calculate the area of a square by raising the side length to the power of 2. For example, a square with the side length of 2 would be 2 x 2 = 4. Find the area of a rectangle by multiplying length times width. For example, a rectangle with a short side length of 4 and a long side length of 10 would be 4 x 10 = 40.
- 3
  Calculate the circumference of a circle by multiplying π and the diameter and rounding the answer. If the radius is provided, multiply it by 2 to find the diameter. For example, for a circle with 3 as the radius: 3(2) = 6 is the diameter, and the circumference is π x 6 = 18.85 (rounded).
- 4
  Square the radius of a circle and multiply by π to find the area of a circle. Note that with a circle with a diameter of 12, you first need to divide by 2 to find that the radius is 6: π x (6 x 6) = 113.1 (rounded).

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