Find the Edges of Your Shape:

First, you need to figure out the boundary or outline of your shape. Imagine outlining the edges of a puddle on the ground with chalk. This is called a contour. Fit a rectangle around the shape:

Once you know the outline, try to fit the biggest possible rectangle around it. Think of wrapping a rubber band tightly around the shape, but only in the form of a rectangle. The rectangle might be tilted, depending on your shape. Adjust the rectangle to the perfect fit:

Use math to ensure the rectangle perfectly matches the shape's boundary at its maximum area. This means it won't just be a simple upright rectangle but could also tilt and turn to fit better. Measure the area:

Once you've drawn the biggest rectangle, measure its width and height and multiply them to get the area. Show It Visually:

Finally, draw this rectangle on the image so you can see what it looks like.