A torch cell is in the shape of .

A candle is in the shape of a _____.

A triangular pyramid whose all faces are equilateral triangles of the same size is called _____.

Verify Euler's formula for the solid.

Verify Euler's formula for the solid.

Verify Euler's formula for the solid.

Using Euler's formula, find the value of $x+y+z$.

A place where two adjacent surfaces of a solid meets is called a/an