What is the value of x if section a = 4x inches, section b = 12 inches, section c = 4 inches and section d = 18 inches in the following picture? pls have explanation

This is what i found “an explicit formula designates the nth term of the sequence, as an expression of n (where n = the term's location). it defines the sequence as a formula in terms of n. this example is an arithmetic sequence(the same number, 5, is added to each term to get to the next term).” i hope this you for what your looking for. can you plz mark me brainliest?