Rules for patterns

We already know the rule for the pattern of letters L,C and F.Some of the letters from Q.1 (given above) give us the same rule as that given by L.Which are these? Why does this happen?

Find the rule which gives the number of matchsticks required to make the following matchstick patterns. Use a variable to write the rule. A pattern of letter T as T

Find the rule which gives the number of matchsticks required to make the following matchstick patterns. Use a variable to write the rule. A pattern of letter Z as Z

Find the rule which gives the number of matchsticks required to make the following matchstick patterns. Use a variable to write the rule. A pattern of letter U as U