The ratio of the radii of two circles is $4: 5$. Then,the ratio of their areas is...........

$A$ field is in the shape of an equilateral triangle in which the length of each side is $70\, m$. $A$ cow is tethered at one of its vertices by a $5\, m$ long rope. Find the area of the region in the field in which the cow can graze. $(\pi = 3.14)$ (in $m^2$)

With respect to the given diagram,which of the following correctly matches the information in Part $I$ and Part $II$?

Part $I$	Part $II$
$1. \overline{OA} \cup \overline{OB} \cup \widehat{APB}$	$a. \text{Major sector}$
$2. \overline{AB} \cup \widehat{AQB}$	$b. \text{Minor segment}$
$3. \overline{AB} \cup \widehat{APB}$	$c. \text{Minor sector}$
$4. \overline{OA} \cup \overline{OB} \cup \widehat{AQB}$	$d. \text{Major segment}$

Nine circular designs are made in a square show-piece as shown in the diagram. If the radius of each circle is $21\, cm$,find the area of the region without design. (in $cm^2$)

Find the difference of the areas of a sector of angle $120^{\circ}$ and its corresponding major sector of a circle of radius $21 \, cm$. (in $cm^2$)

The length of the minute hand of a clock is $12\,cm$. The area of the region swept by it in $5$ minutes is $\ldots \ldots \ldots \,cm^2$. $(\pi=3.14)$