# A Line Example

 We sill start with a simple example.   We will find the area under the horizontal line y = 1 from x = 0 to x = 5.   We know that the answer is 5.   This is the same as We'll need to use the "Area" tool, so click on the "Area" button in the left column.   You should get a window named "Estimate Area Under Curve". Graph the curve y = 1 by entering a 1 in the "y =" text field and pressing the "Graph Your Equation" button. Now we will get a geometric shape, resize it to fit between the curve and the x-axis, and then calculate the area of the shape.   Click once on the blue rectangle in the upper right hand corner of the graphing area. A rectangle will drop out and land on the x-axis. You want to move and resize the rectangle so that it fits (as closely as possible) the area enclosed by the x-axis, y-axis, the line x = 5, and the line y = 1. You move the rectangle by clicking and dragging inside the rectangle's boundaries. You resize the rectangle by clicking and dragging on a corner of the rectangle. Once you have the rectangle sized and positioned correctly, then press the "Calculate Area" button. You should get an answer that is close to 5. Note that any shape that is fully in the graphing window will be added into the area calculation.   You can click and drag extraneous shapes off the screen so that they are not part of the area calculation. Next: Follow the "A Second Line" link.