Since the area is 533, we can put 533 = A + 1/2ps and plug everything else in. A= the area of the base p= perimeter of the base s= slant height, which we are trying to find
533 = (13)(13) + 1/2 (2(13)+2(13)) (s) Now we solve for s. 533= 169 + 26s -169 -169 364 = 26s s = 14
Therefore the slant height would be 14. Hope this helps!