Find the lateral area of a regular pyrmid whose base is a sqauare, whose slant height is 5 m, and whose height is 3 m. I need help.

I think that the answer is 60 . I tried to make a formula, 3(1/2(8 x 5)). I got 8 by subtracting 3 squared from 5 squared and I got 16. I multiplied 4 by 2 and I got 8. I did the formula and I got 60 as my lateral area.