One-Dimensional Figures One dimensional (1-D) figures are lines that lie in one plane and have length in at least one direction. When we check a thermometer to see what the temperature is, it is only measuring data on one plane— temperature. If it gives you another 100 piece of 80 information, like the 60 weather, then this thermometer is measuring in two 40 planes—temperature and weather. So,. 20 it is making two-dimensional 0 measurements. For every plane, you Sunny Cloudy Rainy Snow add you are adding a dimension. If you live in Portland, OR, for example, you experience a temperature segment of -3oF to 107oF. It is called a segment because temperature can be outside of that range, but has never reached lower than the node -3oF or higher than the node 107oF in Portland. Example: • The distance between points A and B, is written as AB • Line AB can have an infinite length, !", which is drawn with arrows on both ends. A B • Line AB can have a node on one end and continue infinitely in the other direction. This type of line is called a ray. A node is a place where a line does not continue and is written as !" or!". Node A B • Joining two rays together in a straight line creates a 1-D line made up of opposite rays. !" and !" are opposite rays that make up the line!". A B C D • Line AB can have nodes on both ends, !". This is called a line segment. A B Practice: 1. Name these objects: !", !", !"# !" 2. Describe a node. 3. If you were to graph the temperature, humidity, and precipitation for a city, how many dimensions would the graph have? 4. Can opposite rays be obtuse? Why or why not? Answers: 1. A line segment AB, a ray AB and a line AB. 2. A node occurs where a line terminates. 3. It would be a 3-Dimensional graph. 4. No, opposite rays form a straight line which are exactly 180 degrees. Obtuse angles are more than 90 and less than (not including) 180 degrees. http://www.icoachmath.com/math_dictionary/One_-_Dimensional_Figure.html http://mathforum.org/library/drmath/view/57250.html http://www.wrh.noaa.gov/pqr/climate/pdx_clisummary.php .