A donut chart displays the value 27 as a proportion of 20 total segments, with blue arcs marking each increment of five and a partial blue arc representing the remainder. The visualization renders in SVG using React and D3 v5, calling the `arc` generator to draw each path. The chart is built by looping through 20 equal segments, filling grey arcs for the unselected portion and blue arcs for the selected value, with white strokes separating each slice.