"Volume and Surface Area of Tetrahedron
'<hr /><div style = "max-width:110mm"><img style="height:60pt;" class="side" alt="tetrahedron.png" src = "https://calcpad.eu/media/math/volume/tetrahedron.png"></div>
'Side length
a = ?
'Volume
V = sqr(2)*a^3/12
'Surface area
S = sqr(3)*a^2 
'1