Question

Please help me with this question

Answer 1

Answer:

422 cm²

Step-by-step explanation:

Surface area of the composite figure = (surface area of the upper cuboid + surface area of lower cuboid) - 2(base area of the lower cuboid)

Surface area of composite figure = $(2(lw + lh + hw)) + (2(lw + lh + hw)) - 2(l*w)$

Upper cuboid has the following dimensions:

$l = 4, w = 3, h = 8$

Lower cuboid has the following dimensions:

$l = 10, w = 7, h = 5$

Plug these values into the formula

Surface area of composite figure

$= (2(4*3 + 4*8 + 8*3)) + (2(10*7 + 10*5 + 5*7)) - 2(4*3)$

$= (2(12 + 32 + 24)) + (2(70 + 50 + 35)) - 2(12)$

$= (136 + 310) - 24$

$= 446 - 24 = 422$

Surface area of composite figure = 422 cm²