The triangular prism shown has triangular face(s) and lateral face(s).

The area of one triangular face is mm2.

The surface area of the triangular prism is mm2.

Element a has no reactivity because it has eight valence electrons and cannot gain anymore electron and it wouldn't lose any either

The median segment divides the triangle into 2 isosceles triangles and everything else is trivial.|ad|=|bc|2=|bd|soδadb  is isosceles with∠dab=∠dbasimilarlyδadc  is isosceles with  ∠dac=∠dca∠cab=∠cad+∠bad=∠acb+∠abctherefore∠cab  is a right angleandbc  is the hypotenuse of a right-angled triangle.hope this