Geometry is the mathematical study of size, shapes and planes. Part of geometry is the different dimensions as they are represented by axises. A two-dimensional figure is drawn on the x- and y-axises, and a three-dimensional figure is drawn on the x-, y-, and z-axises. While there are many two-dimensional figures, this guide will explain the features of a two-dimensional shape.
Comprised of line segments
A shape is comprised of line segments. A line segment is finite and is a straight line connecting two points. These line segments are joined together to enclose an area.
Has more than two sides
To be a shape, the figure must be comprised of more than two segments. If a figure has only two line segments, it is only an angle. A figure with three or more sides is called a polygon. Some polygons have specific names; for example, a three-sided figure is called a triangle and a four-sided figure is called a rectangle.
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All polygons have interior angles. These angles help determine what kind of polygon the shape is. Angles are measured in degrees. For example, if the length of the sides and interior angles are the same, then it is a regular polygon. If the length of the sides and the interior angles are different, then it is an irregular polygon.
The space that is enclosed within the shape is called the area. All shapes have area, though the equations to calculate to find area differ from shape to shape. For example, you calculate the area of a rectangle by multiplying the height by the width and a triangle by multiplying one half of the base by the height.