The picture on the left below shows the Hangzhou International Conference Center, which is the largest spherical building in the country. Figure 1 is the axial section of the sphere. It is known that

The picture on the left below shows the Hangzhou International Conference Center, which is the largest spherical building in the country. Figure 1 is the axial section of the sphere. It is known that the height of the sphere is 86 meters.

Connect OA

∵OA 2 =AD 2 OD 2

∴AD 2 =OA 2 -OD 2 =50 2 - (86-50) 2 =1204 (3 points)

∴S=πAD 2 =1204π square meter. (3 points)

Answer: The building area of ??this international conference center is 1204π square meters. (2 points)