An Architect Wishes to Design a Large Room 148 Feet

Multiple Choice

An architect wishes to design a large room 148 feet long that will be a whispering gallery. The ceiling of the room has a cross section that is an ellipse whose foci are to be located 20 feet to the right and the left of center, as shown in the following figure where d is 148 feet and x is 20 feet. Find the height h of the elliptical ceiling (to the nearest tenth of a foot) .

A) 128.0 feet
B) 276.0 feet
C) 74.3 feet
D) 54.0 feet
E) 71.2 feet