Inside of.
In math, interior means the inside part of a shape or figure. It refers to everything that lies within the boundaries.
For example:
- The interior of a circle is the space inside its curved edge.
- The interior of a rectangle is the region inside its four sides.
- An interior angle is an angle inside a polygon.
We often use the word interior when:
- Finding area (which measures the interior of a shape)
- Studying interior angles of triangles and polygons
- Comparing inside and outside regions
Understanding interior helps us describe where something is located in relation to a shape’s boundary.
When Do Students Learn About “Interior” in Math?
Students begin learning about interiors as they explore shapes and geometry.
Grades 3–5 – Exploring Interior Regions and Angles
Students identify interior regions when finding area and begin learning about interior angles in polygons.
Grades 6+ – Working with Interior Angles in Geometry
Students calculate interior angles of polygons and explore angle relationships in parallel lines and transversals.
