An arch bridge crosses a river. The bridge is supported at each end and has seven additional supports in the water. The span of each arch is 86 meters, and the width of each support at the base is 2 meters. What is the distance across the river?

706 meters

Step-by-step explanation:

An arch bridge crosses a river. The bridge is supported at each end and has seven additional supports in the water. The span of each arch is 86 meters, and the width of each support at the base is 2 meters. What is the distance across the river?

Given that :

Total number of supports on the bridge = 1 at both end + 7 additional = (1 + 7 + 1) = 9 supports

Span of arch = 86 meters

Arch lies in between two successive supports ;

Hence, number of archs = 8

Hence, width of arch = (8 * 86) = 688 meters

Width of support = 2 meters

Total width of support : (2 * 9) = 18 meters

Hence, total distance of bridge :

Total arch width + total support width

(288 metres) + (18 meters) = 706 meters