How would you define balanced sentences?
Could you give me some examples?
Balance in writing sentences is generally called "parallelism". OWL the online writing lab has this definition.
"Parallel structure means using the same pattern of words to show that two or more ideas have the same level of importance. This can happen at the word, phrase, or clause level. The usual way to join parallel structures is with the use of coordinating conjunctions such as "and" or "or." "
An example from that site would be
Not Parallel: Mary likes hiking, swimming, and to ride a bicycle.
Parallel: Mary likes hiking, swimming, and riding a bicycle.
For further examples"
w w w . o w l. e n g l i s h. p u r d u e. e d u / h a n d o u t s / g r a m m a r / g _ p a r a l l e l. h t m l