On s'intéresse au carré ci-dessous :
{"init": {"range": [[-2.0, 12.0], [-2.0, 12.0]], "scale": [20, 20]}, "path": [[[[0.0, 0.0], [0.0, 10.0], [10.0, 10.0], [10.0, 0.0], [0.0, 0.0]], {"fill": "lightskyblue"}], [[[0.0, 0.0], [0.0, 8.0], [8.0, 8.0], [8.0, 0.0], [0.0, 0.0]], {"fill": "#ff4a4a"}], [[[0.0, 0.0], [0.0, 0.5], [0.5, 0.5], [0.5, 0.0], [0.0, 0.0]]], [[[0.0, 10.0], [0.0, 9.5], [0.5, 9.5], [0.5, 10.0], [0.0, 10.0]]], [[[10.0, 10.0], [10.0, 9.5], [9.5, 9.5], [9.5, 10.0], [10.0, 10.0]]], [[[10.0, 0.0], [9.5, 0.0], [9.5, 0.5], [10.0, 0.5], [10.0, 0.0]]], [[[0.0, 8.0], [0.0, 7.5], [0.5, 7.5], [0.5, 8.0], [0.0, 8.0]]], [[[8.0, 8.0], [8.0, 7.5], [7.5, 7.5], [7.5, 8.0], [8.0, 8.0]]], [[[8.0, 0.0], [7.5, 0.0], [7.5, 0.5], [8.0, 0.5], [8.0, 0.0]]]], "line": [[[8.0, 8.0], [8.0, 10.0], {"subtype": "segment", "stroke-dasharray": "-"}], [[8.0, 8.0], [10.0, 8.0], {"subtype": "segment", "stroke-dasharray": "-"}], [[4.32, 8.32], [3.68, 7.68]], [[0.0, 8.0], [8.0, 8.0], {"subtype": "segment"}], [[8.32, 3.68], [7.68, 4.32]], [[8.0, 8.0], [8.0, 0.0], {"subtype": "segment"}], [[5.4, 10.4], [4.6, 9.6]], [[5.0, 10.4], [4.199999999999999, 9.6]], [[0.0, 10.0], [10.0, 10.0], {"subtype": "segment"}], [[10.4, 4.6], [9.6, 5.4]], [[10.4, 5.0], [9.6, 5.800000000000001]], [[10.0, 10.0], [10.0, 0.0], {"subtype": "segment"}], [[10.5, 10.0], [10.5, 8.0], {"subtype": "segment", "arrow-end": "classic-wide-long", "arrow-start": "classic-wide-long"}], [[10.0, 10.5], [8.0, 10.5], {"subtype": "segment", "arrow-end": "classic-wide-long", "arrow-start": "classic-wide-long"}]], "label": [[[10.5, 9.0], "a", "right", {}], [[9.0, 10.5], "a", "above", {}]]}
L'aire totale de la figure bleue + rouge est de \( 39 \).
Donner l'expression littérale non développée, en fonction de \( a \), permettant de calculer l'aire en
rouge.