Answer:
510 square meters
Explanation:
You can divide this figure into a number of 2D shapes which you know how to find the area of.
The two triangular sides of the prism each have areas 12*5/2=30 square meters. The area of the rectangle formed by the smaller leg has area 5*15=75 square meters. The area of the rectangle formed by the larger leg has area 12*15=180 square meters. The area of the rectangle formed by the hypotenuse has area 13*15=195 square meters. Adding all of this together, you get:
30+30+75+180+195=510 square meters. Hope this helps!