The bottom side is 5, because the length of the longer side is 8, and the shorter side is 3, so 8-3=5. The height of the triangle is 5. Use the area formula of a triangle: 1/2*base*height, and you get 1/2*5*5. 1/2 of 5 is 2.5, 2.5 times 5 iss 12.5
Simply set up a proportion. 1/3 = x/48. Cross multiply afterwards. 48 = 3x. Solve the equation. x = 16. By using proportions which is another form of a ratio you can easily find out that there are 16 adults at the school. Hope this helps :))