Question: how to calculate area of an irregular land?
Answer: Step 1: Measure all sides of the area in one unit (Feet, Meter, Inches or any other).
Step 2: Enter length of horizontal sides into Length 1 and Length 2. And Width of the vertical sides into Width 1 and Width 2. ... 
Step 3: Press calculate button. ... 
Our Formula: Area = b × h.