- The surface area of a rectangular prism is calculated by adding the areas of all six faces. The formula is 2(lw + lh + wh), where l is length, w is width, and h is height.
- For problem 1 (l=6, w=4, h=3): 2(6*4 + 6*3 + 4*3) = 2(24 + 18 + 12) = 2(54) = 108 square units.
- For problem 2 (l=5, w=5, h=8): 2(5*5 + 5*8 + 5*8) = 2(25 + 40 + 40) = 2(105) = 210 square units.
- For problem 3 (l=7, w=2, h=5): 2(7*2 + 7*5 + 2*5) = 2(14 + 35 + 10) = 2(59) = 118 square units.
- For problem 4 (l=10, w=4, h=6): 2(10*4 + 10*6 + 4*6) = 2(40 + 60 + 24) = 2(124) = 248 square units.
- For problem 5 (l=8, w=3, h=2): 2(8*3 + 8*2 + 3*2) = 2(24 + 16 + 6) = 2(46) = 92 square units.
- For problem 6 (l=9, w=4, h=7): 2(9*4 + 9*7 + 4*7) = 2(36 + 63 + 28) = 2(127) = 254 square units.
- For problem 7 (l=12, w=5, h=3): 2(12*5 + 12*3 + 5*3) = 2(60 + 36 + 15) = 2(111) = 222 square units.
- For problem 8 (l=6, w=3, h=4): 2(6*3 + 6*4 + 3*4) = 2(18 + 24 + 12) = 2(54) = 108 square units.
- For problem 9 (l=8, w=6, h=5): 2(8*6 + 8*5 + 6*5) = 2(48 + 40 + 30) = 2(118) = 236 square units.
- For problem 10: The gift box has dimensions 10 in (length), 6 in (width), and 4 in (height). The surface area is 2(10*6 + 10*4 + 6*4) = 2(60 + 40 + 24) = 2(124) = 248 square inches. Therefore, 248 square inches of wrapping paper are needed.
Parent Tip: Review the logic above to help your child master the concept of surface area of rectangular prism worksheet.
