Find the surface area, including the floor, of his tent

1.5 x 5 x 2.6 / 2 would be the equation for the Triangle, because we can look for the area if it was a square and divide it by two, 1.5 x 5 = 7.5 and 7.5 x 2.6 = 19.5, now all we need to do is divide it by 2, because the equation I used would be used to find the area of a rectangular prism, and because a triangular prism is half of a rectangular prism, we just need to divide 19.5 by 2, so... 19.5 /2 = 9.75

(If I am wrong, please just tell me so I can fix it, please don't report this)

I hope this helps!