An interior angle usually refers to the angle inside a polygon formed by two adjacent sides. It's most common in math, but the term is also used in sports.

A rhombus is a parallelogram with all four sides equal.

What exactly does 0 mean in math? 0 is the smallest non-negative integer in the set of integers, representing 'nothing' or 'the starting point'.

A hexagon is a flat shape with six sides and six angles, and it's very common in everyday life. For example, a bee's honeycomb and snowflake crystals are typical regular hexagon structures, which are not only beautiful but also save materials.

A helix is a twisted curve that looks like a coil or a screw, and it's a shape commonly seen in biology, for example in DNA and various proteins. Helices can be left-handed or right-handed. Looking along the helix's axis from the center, if the spiral goes counterclockwise from near to far, it's left-handed; if it's the other way around, it's right-handed.

Aesthetics (Greek: αισθητική; English: Aesthetic) is a sub-discipline of philosophy founded by the German philosopher Alexander Gottlieb Baumgarten in 1750. It was initially defined as the science of sensory knowledge (Ästhetik). The Greek root 'aesthesis' means sensory perception, and its study covers aesthetic activities, philosophy of art, and the world of imagery. Baumgarten's concept of 'sensory science' emphasizes that sensory cognition grasps the completeness of relationships between things in a quasi-rational way. Meanwhile, the French scholar Charles Batteaux in 1746 first proposed a system of 'fine arts' covering poetry, painting, and other forms. Hegel limited aesthetics to the philosophy of fine art, while Kant established the independent status of aesthetic judgment in the Critique of Judgment.

Density refers to the mass of a substance per unit volume, usually represented by the symbol ρ, and the international unit is kilograms per cubic meter (kg/m³).

Cryptography is the technical science that studies how to encrypt and decrypt information. Simply put, it's about figuring out how to hide information so others can't understand it, and how to restore the hidden information.

Power refers to the form of a number multiplied by itself several times.

Area refers to the size of the space that an object's surface or a closed shape occupies on a two-dimensional plane, used to measure how much a 2D region is covered.