Thanks.What formula do i use to sum everything to right or the left of the diagonal?

Thanks for finally writing about >How to sum diagonal of a range in Excel?

Thank you so much for your good information, I would like to know how I can multiply a triangular range say a triangle SUM of triangle A1,E1,A5, (this triangle is static and used as the "multiplier"). So this range of cells multiplies the range of cells G1,K1,G5 then the results are put in the range of cells I1,M1,I5. Once this is done I want to be able to slide down the triangle G1 because G2, K1 becomes K2 and G5 becomes G6. and so on with all the results put in the triangle where I1 become I2 and so on. Thank you so much for your help

This is great! how can I SUM the triangle in figure 2? Imagine a triangle that has the following 3 corners A1 D1 A4 thank you so much!!!

Hi there, What would the formula be if I wanted for 2nd scenario if the matrix started on, say, D22? In other words, how do I compensate for larger row/column numbers than starting at 1 (ie A1)? Thanks, Karl