The scale factor of two similar triangles (or any geometric shape, for that matter) is the ratio between two corresponding sides. In today's lesson, we will show that this same scale factor also … [Read more...] about Applying the Scale Factor of Similar Triangles to the Perimeter

# Perimeter of Geometric Shapes

The perimeter of geometric shapes is the length of the line defining the shape, or the distance around the shape.

For example, the perimeter of a rectangle is given by:

For polygons, it is the sum of the lengths of all the straight lines that make up the polygon.

For circles, the perimeter is called the circumference, and it is given by the formula C=2*r*π , where r is the circle's radius, and π is a special mathematical constant, which is not a rational number, roughly equal to 3.14159.

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*Now that we've explained the basic concept of perimeter in geometry, let's scroll down to work on specific geometry problems relating to this topic.*

## Perimeter of a Polygon

The perimeter of a polygon is the combined length of all its straight-line sides. In many geometry problems, we are asked to find the perimeter of an irregular shape, where not all of the side lengths … [Read more...] about Perimeter of a Polygon

## Perimeter of a Rectangle

The perimeter of any polygon is simply the combined lengths of all its sides. In a polygon like a rectangle or a parallelogram, where the two opposite sides are equal, this can be simply represented … [Read more...] about Perimeter of a Rectangle

## Perimeter of Geometric Shapes: Word Problems

It is common to see geometry word problems related to the perimeter of geometric shapes. These problems attempt to connect the concept of perimeter to real-life problems. Here is one such … [Read more...] about Perimeter of Geometric Shapes: Word Problems