Question

three cubes each of sides 7 cm are joined end to end.find the surface of area of the resulting solid.​

Answer 1

GIVEN :-

3 cubes of side 7cm are joined in end to end manner.

TO FIND :- Surface area of large cuboid formed.

SOLUTION :-

If three cubes are joined in end to end manner then It would become a large cuboid having

Length = 7 × 3 = 21cm

Breadth = 7cm

Height = 7cm

Now, we shall find its surface areas :-

1. TOTAL SURFACE AREA (TSA)

TSA( cuboid ) = (LB + BH + HL)2

= (21 × 7 + 7 × 7 + 7 × 21)2

= (147 + 49 + 147)2

= 343 × 2

= 686cmsq. (ans)

2. LATERAL SURFACE AREA (LSA)

LSA (cuboid) = 2(L+B)H

= 2 × 7 ( 7+21)

= 14 × 28

= 392cmsq. (ans)