I have two questions I need help with. They are for a pre-calc class....

1) A building has an entry with the shape of a parabolic arch 4ft high and 26ft wide at the base. Find an equation for the parabola if the vertex is at the origin of the coordinate system.

2) A cross-section of an irrigation canal is a parabola. If the surface of the water is 33ft wide and the canal is 14ft deep in the center, how deep is it 1ft from the edge?

If anyone can help it would be much appreciated. Thanks!