Geometry:

Each of the sp³ hybridized orbitals has similar shape - a rather deformed looking dumbbell.  This deformed dumbbell looks much more like a p orbital than an s orbital because more p orbitals were included in the mixing process.

Figure: sp³ Hybridized orbital.

Each sp³ orbital will take place a space as far apart from each other as possible through pointing to the corners of a tetrahedron. At this time, only the main lobe of each hybridized orbital has been displayed and the angle among each of these lobes is 109.5^o. This is what is meant through the expression tetrahedral carbon. The three- dimensional (3D) shape of the tetrahedral carbon can be presented by drawing a normal line for bonds in the plane of the page. Bonds going behind the page are presented through a hatched wedge, and bonds coming out the page are presented through a solid wedge.

Figure:   Tetrahedral shape of a sp³ hybridized carbon