Estimation of Area with ICT

Author:
Lew W. S.
This problem is taken from Practice Now 8, page 86, think Mathematics 1A, (New Syllabus Matheamatics 8th Edition) SL Education 2020. Students are asked to estimate the percentage of the figure below that is shaded. In using Geogebra's polygon tool which automatically calculates the area of any n-sided polygon drawn with the tool, the user has to draw straight lines (sides of the polygon) over the curved edges of the figure and shaded portion. Try looking at the points and edges of the polygons forming the curved shape and shaded area. Drag to change the position of the points. Is the area calculated also changed? Is the area overestimated or underestimated in your opinion? How do you know ?