Find the value of x someone please help

Can someone pls ! pls answer all. no explanation needed..

A3-dimensional figure has a square base and 4 lateral faces that meet at a point. explain the difference between the cross sections when a slice is made perpendicular to the base through the vertex, and when a slice is made perpendicular to the base and not through the vertex

How can (square root of 25) ^2 be rewritten?