Final answer:
The percentage of a circle that is shaded can be determined by comparing the area of the shaded region to the area of the whole circle, sometimes represented in a pie chart for data like CO₂ sequestration.
Step-by-step explanation:
Calculating what percentage of the circle is shaded involves understanding the area of the circle and the shaded region. If the shaded blue area is set to equal the red area, there must be a specific proportion that the shaded area represents of the full circle.
Consider a circle within a square: the circle has a lesser area than the square but is greater than half of the square (three-quarters for example when using radii to calculate area). Depending on the context given by figures or a graph, one could find the percentage by shading the appropriate region and determining the ratio of that shaded region's area to the area of the whole circle.
To calculate the actual percentage, a textbook, geometrical tools, or integration (in case of non-uniform shading) might be used to compute areas. In statistics, pie charts are quite common for representing proportions, such as the case with CO₂ sequestration data. For example, if the shaded area is half of the circle, the percentage would be 50%.