Answer:
SA = 166 cm²
Step-by-step explanation:
We have three pairs of rectangles:
4cm × 5cm
4cm × 7cm
5cm × 7cm
The formula of an area of a rectangle l × w:
A = l × w
l - length
w - width
Substitute:
A₁ = (4)(5) = 20 cm²
A₂ = (4)(7) = 28 cm²
A₃ = (5)(7) = 35 cm²
The Surface Area:
SA = 2A₁ + 2A₂ + 2A₃
Substitute:
SA = 2(20) + 2(28) + 2(35) = 40 + 56 + 70 = 166 cm²
