Question

Work out the surface area of following shape (use π = 3.14).

Answer 1

To find the total surface area, we draw the figure as given below.

∴ Upper surface area

= 18 × 3 + 8 × 18 + 5 × 18

= 54 + 144 + 90

= 288 cm²

∴ Lower surface area = 288 cm²

∴ Surface area of those faces which are flat from right

= 18 × 18 + 2 × 18 + 3 × 18

= 324 + 36 + 54

= 414 cm²

Also, surface area of that face which are flat from left = 414 cm²

Surface area of from face = 18 × 5 + 2 × 8 + 8 × 18 + 3 × 2 + 3 × 18 + 3 × 3

= 90 + 16 + 144 + 6 + 54 + 9

= 319 cm²

Surface area of the black face = 319 cm²

∴ Total surface area = 288 + 288 + 414 + 414 + 319 + 319

= 288 + 1754

= 2042 cm²