Question

Two cubes, each of volume $512c{m}^3$ are joined end to end. Find the surface area of the resulting cuboid.

Answer 1

$\text{Volume of each cube}=512c{m}^3$

$\therefore \text{Side (edge)}=\sqrt[3]{3512}$

$=\sqrt[3]{38^3}=8cm$

Now by joining two cubes, the length of so formed cuboid (l) $=8+8=16cm$

$\text{Breadth (b)}=8cm$

$\text{and height (h)}=8cm$

$\therefore \text{Surface area}=2(lb+bh+hl)$

$=2[16\times 8+8\times 8+8\times 16]c{m}^2$

$=2[128+64+128]c{m}^2$

$=2\times 320=640c{m}^2$