The word "interior angle" is spelled with the IPA phonetic transcription /ɪnˈtɪəriər ˈæŋɡəl/. The first syllable is pronounced with a short "i" sound followed by the stressed "t" sound. The second syllable contains the "ear" diphthong pronounced similarly to "eer" and the final syllable ends with a hard "g" sound. An interior angle is defined as the angle inside of a polygon between two adjacent sides. This word is commonly used in geometry and mathematics.
An interior angle refers to an angle formed within a polygon, specifically, the angle created by two sides of a polygon when they intersect at a vertex on the inside of the figure. In other words, an interior angle is formed on the interior or inside of a polygon, which is typically a closed shape with three or more straight sides.
The measure of an interior angle is determined by the number of sides in the polygon. For instance, in a triangle—an example of a three-sided polygon—there are three interior angles. In a quadrilateral, a four-sided polygon, there are four interior angles, and so on.
To calculate the measure of an interior angle in a regular polygon, meaning all sides and angles are congruent, one can use the formula (n-2) x 180° ÷ n, where "n" represents the number of sides in the polygon. This formula can be applied to determine the size of each interior angle in different polygons.
Understanding interior angles is vital in geometry, as they play a crucial role in the study of polygons and their properties. Interior angles can help determine if a polygon is regular or irregular, as well as assist in solving various geometric problems and formulas involving polygons.
The word "interior" comes from the Latin term "interior", which means "inner" or "internal".
The word "angle" has its roots in the Latin word "angulus", which means "corner" or "angle".
Therefore, the term "interior angle" combines these two words to describe an angle formed on the inside or interior of a geometrical shape, such as a polygon.