Solution 1: Analysis: As shown below, first subtract the area of triangle from the area of a quarter circle to find the area of "semi-lobe", and then multiply the area of "semi-lobe" by 2.
Solution 2: Analysis: The area of "leaf shape" can be regarded as the area of two quarter circles minus the area of a square.
Solution 3: Analysis: Separate the "leaf shape" to form the following figure. That is, a semicircle minus a triangle.
Solution 4: Analysis: First subtract the area of a quarter circle from the area of a square to get the area of a blank part, then subtract the area of a blank part from the area of a square, and multiply by 2 to get the "leaf-like" area.
The leaf area can be calculated by all four methods.