no shape
don't no
A moebus strip.
a face
Redden means to become red.Footnote: This form of the word red is one of very few examples of English as an 'inflecting' or 'fusional' language. In its early history English was highly fusional, meaning that word endings were extensively used in order to indicate the function of a word, similar to Latin. Other words similar to redden are oaken and golden.
tidal lock
The side of your face is called the profile
Pennies have Abraham Lincoln's face on one side. Nickels have Thomas Jefferson on one side. Dimes have Franklin Delano Roosevelt's face on one side. Quarters have Georges Washington's face on them. Half-dollar pieces have John F. Kennedy's face on one side.
To answer this question more details need to be provided. For example one a 3D shape one side is called a face.
stroke
bilaterally symmetrical
An edge.
no shape
One side of the moon is always lit because of a phenomenon called "synchronous rotation," where the moon rotates on its axis at the same rate that it orbits the Earth. This causes one side of the moon to constantly face towards Earth while the other side remains in darkness.
A sphere
A blob.
a line