In mathematics, a geometric progression, also known as a geometric sequence, is a sequence of numbers where each term after the first is found by multiplying the previous one by a fixed, non-one number called the common ratio. For example, sequence 2, 6, 18, 54, ... is a geometric progression with common ratio 3. Geometric progressions all start with a first term and then either increase or decrease by a constant factor called the common ratio. We denote the first term by the letter 'a' and the common ratio by the letter 'r'. Let's now learn how to find the sum of first n terms of G.P. A geometric sequence is a sequence of numbers that follows a pattern where the next term is found by multiplying by a constant called the common ratio, r. Write the first five terms of a geometric sequence in which a1=2 and r=3. The geometric mean of numbers is because an -dimensional cube with that side length has a volume equal to the product of those numbers. That's why "geometric" somehow means "multiply", yielding the name of geometric progression. So, this chapter is going to be completely about G.P., its general term, properties and the sum of terms in a G.P.