Respuesta :

Formula= angle/360° x pi r^2
100/360 = 0.27777778
Radius = diameter/2
9.3/2 = 4.65
Pi x 4.65^2 = 67.9290872 (do not round until the end)
0.27777778 x 67.9290872 = 18.869191
This number rounds to 18.9
Hope this helps
-Emiliaatkinson (UK)