Réponse :

diam = 60m, rayon = 30m, aire exacte = 900πm², aire arrondie = 8882,64 m²

Explications étape par étape :

diam = 60m, rayon = 30m, aire exacte = 900πm², aire arrondie = 8882,64 m²

diam = 0,5m, rayon = 0,25m, aire exacte = 0,0625πm², aire arrondie = 0,20 m²

diam = 60m, rayon = 30m, aire exacte = 900πm², aire arrondie = 8882,64m²

diam = 260m, rayon = 130m, aire exacte = 16900πm², aire arrondie = 53092,92m²

diam = 0,5m, rayon = 0,25m, aire exacte = 625πcm², aire arrondie = 0,20 m²

diam = 55m, rayon = 27,5m, aire exacte = 756,25πcm², aire arrondie = 2375,83 m²