Help- i dont know what it is at all

Pyramid shown has a square base that is 18 inches on each side has a surface area of 164 square inches what is the slant height

If the altitude is drawn to the hypotenuse of a right triangle, then the two triangles formed are similar to the original triangle and to each other. which set of triangles shows the similar triangles created by the altitude in the diagram?

State one method by which you can recognize a perfect square trinomial.