What is the area of the shaded portion if each side of the square measures $21\,cm$? (in $cm^2$)

Two roads $XY$ and $YZ$ of $15 \ m$ and $20 \ m$ length respectively are perpendicular to each other. What is the distance between $X$ and $Z$ by the shortest route? (in $m$)

If the length and breadth of a rectangular plot are increased by $50 \%$ and $20 \%$ respectively,then the new area is how many times the original area?

The breadth of a rectangular plot is $75 \%$ of its length. If the perimeter of the plot is $1050 \, m,$ what is its area (in $, m^2$)?

$A$ wire is in the form of a semi-circle of $7 \, cm$ radius. The length of the wire will be (in $cm$):

The area of a circle is $154 \, cm^{2}$. The length of an arc of the circle which subtends an angle of $45^{\circ}$ at the centre is......$cm$.