Pronunciation: [kɒnkˈe͡ɪv ʃˈe͡ɪp] (IPA) 
Concave shape refers to a surface or curve that curves inward, like the inside of a bowl. The spelling of the word is /kɒnˈkeɪv/ or kahn-kayv. The first syllable is pronounced with a short "o" sound, followed by a "k" sound. The second syllable has a long "a" sound, followed by a "v" sound. Concave shapes can be found in nature, such as the inside of sea shells, or in architecture, such as the domes of buildings.
A concave shape refers to a geometric figure or surface that curves inward or is curved inwards, resembling the interior of a hollow sphere or a cave. It is characterized by having a curved or sunken appearance, where the distance between any point on the surface and the center is greater than the distance between the center and the edge. In concave shapes, the outer edges or sides are curved inwards towards the middle, creating a depression or indentation in the center.
Concave shapes can be found in various objects and natural structures. For instance, a concave lens is thinner in the middle and thicker towards the edges, causing light rays passing through it to diverge and resulting in the objects appearing smaller or further away. Another example is a concave mirror, such as the spherical "funhouse" mirrors, which reflect light inward, making objects appear distorted, enlarged, or even upside down.
In mathematics, a concave shape is defined as a function or a curve having the property that a straight line connecting any two points on the graph lies below or on the curve. This property is commonly used in optimization problems to find maximum values.
Overall, a concave shape describes a form that has a depressed or curved interior, where the edges or sides are curved inward towards the center, creating a distinct hollow appearance.
The word "concave" is derived from the Latin word "concavus", which means "hollow" or "curved inward". It is a combination of the prefix "con-" meaning "with" or "together", and the root word "cavus" meaning "hollow". Hence, "concave" describes a shape that is curved inward or has a surface that is curved like the interior of a hollow object.
