lo puse en mi calculadora esperaba que esto ayudara
By geometry, there is a relationship between the tangent PA and the segments PB and PE, namely
PA^2=PB*PE
so
PE=PA^2/PA=6^2/4=9
BE=PB-PE=9-4=5
Since each edge's length is x, each face's are would be

And cubes have 6 faces. multiply 6 by

, the formula is :
It is an irrational number, as it is neither terminating nor non-terminating recurring.