2.  Substitute the values.  Follow the order of operations. (GPRMDAS)  Use appropriate units. ◦ Perimeter is measured in units. (n units) ◦ Area is measured in square units. (n units² ) ◦ Volume is measured in cubic units. (n units³)

3. l = 20 in w = 12 in V = 1440 in³ V = lwh 1440 = 20(12)h 1440 = 240h 240 6 = h l = 20 in w = 12 in V = 1440 in³ V = l w h 1440 = 20 12 h 1440 = 240 h 240 6 = h h = 6 in

4. l = 20 in w = 12 in h = 6 in SA p = 2(lw + wh + lh) = 2(20∙12 + 12∙6 + 20∙6) = 2(240 + 72 + 120) =2(240 + 120 +72) =2(360 + 72) =2(432) =864 in² l = 20 in w = 12 in h = 6 in SA  sum of areas of all faces lw = 20(12) = 240 in² wh =12(6) = 72 in² hl = 6(20) = 120 in² SA = 240 + 240 + 72 + 72 + 120 + 120 = 480 + 144 + 240 = 720 +144 = 864 in²