Lesson 1: Polygons and Their Properties

Property

A polygon is a closed, two-dimensional figure formed by three or more straight line segments that do not cross each other.

• Sides: The straight line segments that form the polygon.
• Vertices: The points where the sides meet (singular: vertex).
• Angles: The angles formed at the vertices inside the polygon.

Examples

Property

A standard unit of area is a square with a specific side length used for consistent measurement.

• A square inch ($1 \text{ in}^2$) is a square with 1-inch sides.
• A square centimeter ($1 \text{ cm}^2$) is a square with 1-centimeter sides.

Since 1 inch is longer than 1 centimeter, a square inch is a larger unit of area: $1 \text{ in}^2 > 1 \text{ cm}^2$.