Final answer:
A delta is a landform at the river mouth where the river deposits sediment, creating a distinctive triangular shape. It is also a symbol (Δ) used in Mathematics and Science to denote change in a quantity.
Step-by-step explanation:
The term delta refers to an often triangular-shaped section of land at the mouth of a river, created as the waters of the river slow down and split into various channels. This deceleration allows the river to deposit materials such as sand and silt that it has transported downstream. The formation of a delta is a dynamic process that can result in a complex network of ecosystems, such as wetlands, channels, and islands. An example of such a formation is the Delta Ponds in Eugene, Oregon. This 150-acre area has evolved substantially over time, especially due to human interventions such as gravel extraction, which reshaped the landscape into a series of ponds and islands.
In the context of Mathematics and Science, delta (Δ) is also a letter of the Greek alphabet used to denote a change or difference in a certain quantity, suggesting a final value minus an initial value. For instance, Δx signifies the change in variable x, whereas Δt indicates the change in time, t.