Say that you are forming the product A5×3 B3×2 = C5×2
What row and column are used to calculate the 3rd row 2nd column of C ?
The 3rd row of A and the 2nd column of B
Your computer graphics book might show a different way to do matrix-matrix multiplication. There are several ways to think about it, although the results are the same.
The diagram shows another way to visualize the product AB = C. Write A to the left and B above, then draw horizontal lines and vertical lines to divide C into cells. This will automatically form the correct number of cells.
The number to put in each cell is the dot product of the corresponding row of A and column of B .