Octagon Study Guide

Definition: An octagon is a polygon with eight sides and eight angles.
Interior angles: The sum of the interior angles in any octagon is always 1080 degrees.
Regular octagon: A regular octagon is one in which all the sides and angles are equal. Each interior angle in a regular octagon measures 135 degrees.
Formulas:
- Sum of interior angles = (n-2) * 180 degrees
- Each interior angle = Sum of interior angles / number of sides
Properties:
- An octagon has 8 sides and 8 angles.
- The exterior angles of an octagon add up to 360 degrees.

◂Math Worksheets and Study Guides Eighth Grade. Patterns in geometry

Study Guide

The resources above cover the following skills:

Geometry (NCTM)

Analyze characteristics and properties of two- and three-dimensional geometric shapes and develop mathematical arguments about geometric relationships.

Create and critique inductive and deductive arguments concerning geometric ideas and relationships, such as congruence, similarity, and the Pythagorean relationship.

Apply transformations and use symmetry to analyze mathematical situations.

Describe sizes, positions, and orientations of shapes under informal transformations such as flips, turns, slides, and scaling.

Examine the congruence, similarity, and line or rotational symmetry of objects using transformations.