Answer:
382 cm²
Explanation:
The shape can be decomposed into two rectangular prism or cuboids
✔️Dimension of prism 1 (smaller prism):
L = 10 cm
W = 3 cm
H = 7 - 4 = 3 cm
Surface area of prism 1 = 2(LW + LH + WH)
= 2(10*3 + 10*3 + 3*3)
= 2(69)
Surface area of prism 1 = 138 cm²
✔️Dimension of prism 2 (larger prism):
L = 10 cm
W = 8 cm
H = 4 cm
Surface area of prism = 2(LW + LH + WH)
= 2(10*8 + 10*4 + 8*4)
= 2(152)
Surface area of prism 2 = 304 cm²
✅Surface Area of the composite shape = (Surface area of prism 1 + surface area of prism 2) - (2 × area of the base of prism 1)
= (138 + 304) - (2 × L × W)
= 442 - (2 × 10 × 3)
= 442 - 60
= 382 cm²