Topographic+Maps

- topographic maps are detailed, accurate graphic representations of features that appear on the earths surface. They are used for the determination of a point in three dimensional. - Contour lines are **used** to determine elevations and are lines on a **map** that are produced from connecting points of equal elevation (elevation refers to height in feet, or meters, above sea level). ,contour lines connect points of equal height, and show grades of hills, the closer together the lines the steeper the grade. The map legend should tell you the differnece in elevation between lines, this could be in feet or meters.
 * What are topographic maps and what are they used for?**
 * How are contour lines drawn, what are rules for drawing contour lines?**
 * symbols**


 * map scale**

To calculate a percent slope, simply divide the elevation change in feet, by the distance of the line you drew (after converting it to feet). Multiply the resulting number by 100 to get a percentage value equal to the percent ,slope of the hill. If the value you calculate is, for example, 20, then what this means is that for every 100 feet you cover in a horizontal direction, you will gain (or lose) 20 feet in elevation. To calculate the angle of the slope, divide the elevation change in feet by the distance of the line you drew (after converting it to feet). This is the tangent value for the angle of the slope. Apply an arctangent function to this value to obtain the angle of the slope (hit the ‘inv’ button and then the ‘tan’ button on most scientific calculators to get the slope angle). The angle you calculated is the angle between a horizontal plane and the surface of the hill.
 * How is slope determined?**
 * What are the steps to draw a profile?**