Two-dimensional figures, also known as 2D shapes, are flat geometric shapes that have only length and width but no depth. Common examples include squares, circles, triangles, and rectangles. These shapes can be classified based on their properties, such as the number of sides or angles they possess. In mathematics, two-dimensional figures are often studied in the context of geometry. They can be measured for area and perimeter, which are important concepts in various applications, including art, architecture, and engineering. Understanding 2D shapes is fundamental for learning more complex geometric concepts.