How many cubes/blocks are there in below figure?

There are 9 columns with 5 cubes = 9 × 5
There are 7 columns with 4 cubes = 7 × 4
There are 5 columns with 3 cubes = 5 × 3
There are 3 columns with 2 cubes = 3 × 2
There is one column with 1 cubes = 1 × 1
Total = 9 × 5 + 7 × 4 + 5 × 3 + 3 × 2 + 1 × 1 = 81