Question

3 m 3 m 3 m 3m 7 m Find the surface area of the object.​

Answer 1

Answer:

123 m²

Step-by-step explanation:

Surface area of the object = surface area of the bigger rectangular prism + (surface area of the smaller rectangular prism - area of the smaller rectangular prism base)

Surface area of the bigger rectangular prism:

L = 7 m

W = 3 m

H = 3 m

S.A = 2(LW + WH + LH)

S.A = 2(7*3 + 3*3 + 7*3)

S.A = 102 m²

Surface area of the smaller rectangular prism:

L = 3 m

W = 3 m

H = 1 m

S.A = 2(LW + WH + LH)

S.A = 2(3*3 + 3*1 + 3*1)

S.A = 30 m²

Area of the base of the smaller rectangular prism = L*W

L = 3 m

W = 3 m

Area = 3*3 = 9 m²

Surface area of the object = 102 + (30 - 9)

= 102 + 21

= 123 m²