Question: What figure is it
1. The problem asks to identify the figure based on the description and partial calculations provided.
2. From the given data, we see calculations involving areas of squares and circles, and mention of an "L" shaped pool.
3. The first calculation $A=10 \times 10=100$ cm$^2$ suggests a square.
4. The second calculation $C=\pi \cdot r^2 = \pi \cdot 5^2 = 25\pi \approx 78.5$ cm$^2$ indicates a circle.
5. The backyard is described as having an "L" shaped pool, which is a composite figure made by combining rectangles or squares in an L shape.
6. Therefore, the figure described is a composite figure consisting of a square, a circle, and an L-shaped polygon.
Final answer: The figure is a composite figure including a square, a circle, and an L-shaped polygon.