Bridge is build in a shape of a parabolic arch and its span is 140 feet.

The height of the arch a distance of 50 feet from the center is to be 12 feet.

Whats the height of the arch at its center.

* Round to nearest tenth place if necessary.

#1 * Equation of the parabola in standard form.

#2 * Height at center.

How exactly is one suppose to solve this problem?