Y by Adventure10, Mango247
For triangle
, let
be the midpoints of sides
, respectively. Determine which triangles
have the property that triangles
can be folded above the plane of triangle
to form a tetrahedron with
coincides with
coincides with
coincides with
.
Due to LUK Mee Lin, La Salle College










Due to LUK Mee Lin, La Salle College