First of all I wanna point out a minor mistake!
this is not a rectangular prism, the base of this picture is actually the side facing us and the back side. Making this a triangular prism.
We can start by finding the 2 triangles which are the bases.
Each triangle have area:10*24/2
Now because there are 2 same triangles we can get rid of the /2 and get the area of the triangles in the diagram is 10*24=240
We could do the other three sides 1 by 1, let's start with the side on the left of the shape. It has area 24*19=456 because the bottom is a rectangle so we could just use the 19.
Now we can do the side that is diagonal and on the right. It has area of 26*19=494.
Now just 1 more side the bottom, it has area of 10*19=190. Everything is in cm^2 as a unit because we are dealing with area.
Now we just need to add everything together.
240+456+494+190= 1380
Hope it helps! any questions about my answer please just leave in the comment I will get to it when I have time.
