# 6 Measure lake area

#### Step 1

From the ImageJ Menu select Analyze

Measure. The Area of the lake is listed in the Results window.

If the Results window is not visible select Window Results from the menu.

#### Step 2

Click on the Lake_July_1978 image to make it active. Follow STEPS 1 to 6 to trace around the same lake and measure it when finished. The area of both lakes, in m2 will be listed in the Results window.

**Question 1. **The area of a football field is 5348 m2 . Is the amount of change in the lakes greater or less than the area of a football field?

- Roll-over for Answer:
- Less

**Question 2. **1. Calculate the percent change from 1978 to 2008 and compare it to your estimated answer from question.

2. Use the formula: (1978 area – 2008 area) / 1978 area) x 100

- Roll-over for Answer:
*Answers will vary somewhat depending on the accuracy of the measurement. *

(14791m2 – 10893m2) / 14791m2 = 26.3%