An easy way to remember parallel lines is to think of “equal to (=)” sign. This is the reason we call 90° as a right angle.Ģ. Have you ever wondered why 90° is called a right angle? When two lines intersect each other, they form two angles, and when the angles formed are equal, then it is a fair or “right” situation. This article will explain the various aspects of perpendicularity and its two types in detail. Angularity and parallelism are other callouts in orientation control besides perpendicularity. Orientation controls define the orientation of a feature with reference to a datum plane or axis. Through the given diagram, we can visualize the difference between perpendicular and non-perpendicular lines. Perpendicularity is a type of orientation control. In geometry, perpendicular lines are represented using the symbol ‘’.Įxample 1: The given picture shows the perpendicular lines in the floor tiles.Įxample 2: In the given picture, the vertical and the horizontal lines (black and pink) in the English alphabet ‘H’ are perpendicular lines. Lines which meet (intersect) each other at right angles are called perpendicular lines. The two diagonals of a rhombus are perpendicular that is, a rhombus is an orthodiagonal quadrilateral. It follows that any rhombus has the following properties: Opposite angles of a rhombus have equal measure. Some examples are the sides of a set square, the arms of a clock at certain times of the day, the corners of the blackboard, a window, and the Red Cross symbol. The Perpendicular Symbol is also closely related to flatness when referenced/measured surface is a surface plane. We can observe many perpendicular lines in real life. All of the orientation symbols (Angularity, Parallelism, and Perpendicularity) all call out the particular feature envelope referenced to a datum. Lines which meet or appear to meet when extended are called intersecting lines and the point where they meet is called the point of intersection. Every rhombus has two diagonals connecting pairs of opposite vertices, and two pairs of parallel sides. Perpendicularity is a specific form of Angularity at 90. As they never meet, the distance between the parallel lines remains constant.Įxample 1: In the given picture, the rails of the railroad track represent parallel lines as the distance between the rails remains the same.Įxample 2: Lines of a writing pad are another example of parallel lines.Įxample 3: In the given picture parking line stripes show parallel lines. Lines in a plane that never meet, even if we extend them, are called parallel lines. While a circle or a ellipse can informally be considered a polygon with infinitely many sides, it technically is not a polygon.Two lines in a plane either meet on extending or do not meet at all. A circle is a special ellipse in which the two focal points overlap. The two fixed points are called the focal points. EllipseĪn ellipse is a 2D curve in which all of the points on the curve lie the same total distance from two fixed points. The fixed point is called the center of the circle, and the distance from the center to any point on the circle is called the radius. The irregular pentagon above has sides and interior angles that are not all congruent.Ī line containing any side of the polygon does not intersect the interior of a convex polygon.Ī least one line containing a side of a concave polygon intersects its interior.Ī circle is a 2D curve in which all of the points on the curve lie the same distance from a fixed point. The regular pentagon above has five congruent sides and five congruent interior angles. Polygons classified by shape Regular polygon Polygons can be further classified based on their characteristics. PolygonsĪ polygon is a closed 2D figure formed by three or more non- collinear line segments, called sides. The following are some important 2D shapes. Closed 2D shapesĬlosed 2D shapes are studied extensively in geometry. Comparatively, an open shape means at least one endpoint of one side is not connected to the rest.

A closed shape means its sides are connected from end to end with no break in the connection. Home / geometry / plane / 2d shapes 2D shapesĪ 2D shape is a shape that lies in a plane and only has a length and a width, but no height or depth.ĢD shapes can be classified as closed shapes and open shapes.

Perpendicular shapes