This question is painfully difficult.

Volume of pyramid is 1/3 times base area x height

Then 1/3 x 16 x 14 x h = 700

You should get h = 75/8

From there, however, things go downhill.

There are four triangular surfaces. Two of them have the same area, and another two have the same area. There are two different slant heights to obtain depending on whether the base surface of the triangle is 16 cm or 14 cm.

The area of two of the triangles is
2 x 1/2 x 16 x slant1

where slant1 = sqrt [(75/8)^2+ 16^2].

The area of the other two triangles is
2 x 1/2 x 14 x slant2

where slant2 = sqrt [(75/8)^2 + 14^2].

The base square has area 16 x 14 = 224.

Add these up for the area.

the answer is 584cm^2

If no one does this by tomorrow night, I will write up the workings

nevermind, someone msg me an answer already.. Thank you though :>