**Question:**

Fill in the blanks.

(i) If *l*, *b*, *h* be the length, breadth and height of a cuboid, then its whole surface area = (.......) sq units.

(ii) If *l*, *b*, *h* be the length, breadth and height of a cuboid, then its lateral surface area = (.......) sq units.

(iii) If each side of a cube is *a*, then its lateral surface area is ....... sq units.

(iv) If *r* is the radius of the base and *h* be the height of a cylinder, then its volume is (.......) cubic units.

(v) If *r* is the radius of the base and *h* be the height of a cylinder, then its lateral surface area is (......) sq units.

**Solution:**

(i) If $I, b$ and $h$ are the length, breadth and height of a cuboid, respectively, then its whole surface area is equal to $2(l b+l h+b h)$ sq units.

(ii) If $I, b$ and $h$ are the length, breadth and height of a cuboid, respectively, then its lateral surface area is equal to $2((l+b) \times h)$ sq units.

(iii) If each side of a cube is $a$, then the lateral surface area is $4 a^{2}$ sq units.

(iv) If $r$ and $h$ are the radius of the base and height of a cylinder, respectively, then its volume is $\pi r^{2} h$ cubic units.

(v) If $r$ and $h$ are the radius of the base and height of a cylinder, then its lateral surface area is $2 \pi r h$ sq units.