It's best to use a printed version of the orbital plot. It is easier to measure and you don't have to worry about accidentally resizing the plot between measurements. If you are trying to measure on a screen, be sure not to resize the plot until completing the lab. Using a ruler, in millimeters, carefully measure the bases and heights of both the shaded triangles that are indicated on the plot and write them down. Note how to measure the height of the thin triangle as shown on Figure 3. Estimate to the nearest 10th of a millimeter. (Recall that the numbers on the ruler indicate centimeters. The 10 marks between the numbers is millimeters.) Using Equation 2, calculate the areas of each triangle using the bases and heights you measured. The percent difference is calculated using the following Equation