Molecular shape structures - As far as an A level student needs to know.

Tetrahedral

(E.g. Methane CH4)

109 degrees apart.

Pyramidal

(E.g. Ammonia)

109 degrees apart.

Bent

(E.g. Water)

104 degrees apart.

Linear

(e.g. BeCl2)

180 degrees apart

Planar Triangular 

(E.g. BF3)

120 degrees apart, and two dimensional

Trigonal bipyramidal

(E.g. Phosphorus Pentachloride)

120, or 90 degrees apart

Octahedral

(E.g. Sulfur hexafluoride)

90 degrees apart on all planes.

Quick Guide to Molecule Shapes

A general example in Methane:

Where the firm lines resemble what lies on the 2D plane.

The dotted line resembles what lies backwards.

The Wedge resembles what lies forwards.

Making Methane actually look like this:

We use these denotations because molecules in real life are actually 3 Dimensional. 

n.b. Lone pairs are very important in atoms in molecules because they define what else the atom can bond with.