Answer:

Given,

Top of the towers are 30 m above the roadway and are 200 m apart.

Cable is 5 m above the roadway at centre.

A and B are the top of the towers. AE and BF are the height of the towers. H is the centre of the bridge.

HI is the 5 m above from the roadway.

The equation of the parabola, x² = 4a(y – b)

b = 5

x² = 4a(y – 5)

AB = 200 m

BF = 30 m.

The coordinate of the point B is (100, 30)

The point is on the parabola.

x² = 4a(y – 5)

10000 = 4a (30 – 5)

10000 = 4a (30 – 5)

10000 = 4a x 25

a = 100

The x-coordinate of the point, 30 m from the centre, is 30.

30 x 30 = 4a (y – 5)

900 = 400 (y – 5)