The total area of a box is the sum of all the area of the faces it has. It is also called the surface area. The area of one face of a rectangular box is equal to the product of its length and width. So, the total area would be:
SA = 2lw + 2wh + 2lh SA = 2(4)(3) + 2(3)(6) + 2(4)(6) SA = 108 ft^2
Diana's age=21 years Carmen's age=x years Andrew's age=2x years 21+x+2x=45 21+3x=45 3x=45-21 3x=24 x=24/3 x=8 2x8=16 Carmen is 8 years old and Andrew is 16 years old. Hoped that helps:)