To determine the surface area of a rectangular prism, the Equation is: Surface Area = (length x width + width x height + length height)x 2
The surface area with: length of 2(5 x 3), a width of 2(5 x 8), a height of 2(3 x 8) SA = 2(15) = 30, SA = 2(40) = 80, SA = 2(24)= 48, SA = 30 + 80 + 48 SA = 158 square units.
SA = 2LW + 2LH + 2HW SA = 2(5 x 3) + 2(5 x 8) + 2(3 x 8) SA = 2(15) + 2(40) + 2(24) SA = 30 + 80 + 48
In the ratio 2:3 going to 28:? there is a pattern. You multiply 2 by 14 to get to 28, so if you multiply 3 by 14 you get 42. Add 42 to 28 for the total amount of students in class!