Given the ratio, you know that: length = 6x width = 2x height = 7x
Because the sum of the length and the width is 24 cm, you can write the equation: 6x + 2x = 24 Solve: 8x = 24 x = 3
Plug the 3 back into the expressions written earlier for length, width, and height. length = 18 cm width = 6 cm height = 21 cm
Use the formula SA = 2B + Ph to solve for the surface area. Surface Area = 2(area of the base) + (perimeter of the base)(height)
I'm going to plug in l, w, and h as variables for length, width, and height to show the exact way to solve for the B and P. SA = 2lw + 2(l + w)h SA = 2(18)(6) + 2(18 + 6)(21) SA = 216 + 2(24)(21) SA = 216 + 1008 SA = 1224
