Who can answer this maths question?
In the figure, the shape of the steel wire of a bridge is a parabola, and the two main poles with a height of 90 m each are 600 m apart. If the steel wire just touches the ground at the centre of the bridge, is it more than 20 m above the ground at the position of 100 m away from the centre of the bridge? Explain briefly.
(tips: the bridge looks like a graph of quadratic functions which one of the point is (300,90) and the vertex is (0,0). )